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185-405: Psychopathy , or psychopathic personality , is a personality construct characterized by impaired empathy and remorse , in combination with traits of boldness , disinhibition , and egocentrism . These traits are often masked by superficial charm and immunity to stress , which create an outward appearance of apparent normalcy. Hervey M. Cleckley , an American psychiatrist , influenced
370-552: A biological basis of human personality. If personality traits are unique to the individual culture, then different traits should be apparent in different cultures. However, the idea that personality traits are universal across cultures is supported by establishing the Five-Factor Model of personality across multiple translations of the NEO-PI-R, which is one of the most widely used personality measures. When administering
555-415: A clinical measuring tool to diagnose psychiatric disorders and help with prognosis and therapy planning. Personality is frequently broken into factors or dimensions, statistically extracted from large questionnaires through factor analysis . When brought back to two dimensions, often the dimensions of introvert-extrovert and neuroticism (emotionally unstable-stable) are used as first proposed by Eysenck in
740-442: A continuum, and thus characterize the personality of philosophers of each camp. The "mental make-up" (i.e. personality) of rationalist philosophers is described as "tender-minded" and "going by "principles", and that of empiricist philosophers is described as "tough-minded" and "going by "facts." James distinguishes each not only in terms of the philosophical claims they made in 1907, but by arguing that such claims are made primarily on
925-424: A culture can also be useful evidence for the universality of traits across cultures, as the same underlying factors can still be found. Results from several European and Asian studies have found overlapping dimensions with the Five-Factor Model as well as additional culture-unique dimensions. Finding similar factors across cultures provides support for the universality of personality trait structure, but more research
1110-521: A decreased activation of the fusiform and extrastriate cortical regions. The underlying biological surfaces for processing expressions of happiness are functionally intact in psychopaths, although less responsive than those of controls. The neuroimaging literature is unclear as to whether deficits are specific to particular emotions such as fear. The overall pattern of results across studies indicates that people diagnosed with psychopathy demonstrate reduced MRI, fMRI, aMRI, PET, and SPECT activity in areas of
1295-486: A diagnosis titled "psychopathy", assessments of psychopathic characteristics are widely used in criminal justice settings in some nations and may have important consequences for individuals. The study of psychopathy is an active field of research. The term is also used by the general public, popular press, and in fictional portrayals . While the abbreviated term "psycho" is often employed in common usage in general media along with "crazy", " insane ", and "mentally ill", there
1480-515: A disposition that generally leads them to experience a higher degree of positive affect. In their study of extraversion, Lucas and Baird found no statistically significant support for the instrumental theory but did, however, find that extraverts generally experience a higher level of positive affect. Research has been done to uncover some of the mediators that are responsible for the correlation between extraversion and happiness. Self-esteem and self-efficacy are two such mediators. Self-efficacy
1665-441: A final resort, plot digitizers can be used to scrape data points from scatterplots (if available) for the calculation of Pearson's r . Data reporting important study characteristics that may moderate effects, such as the mean age of participants, should also be collected. A measure of study quality can also be included in these forms to assess the quality of evidence from each study. There are more than 80 tools available to assess
1850-497: A fitness chain to recruit a large number participants. It has been suggested that behavioural interventions are often hard to compare [in meta-analyses and reviews], as "different scientists test different intervention ideas in different samples using different outcomes over different time intervals", causing a lack of comparability of such individual investigations which limits "their potential to inform policy ". Meta-analyses in education are often not restrictive enough in regards to
2035-429: A free software. Another form of additional information comes from the intended setting. If the target setting for applying the meta-analysis results is known then it may be possible to use data from the setting to tailor the results thus producing a 'tailored meta-analysis'., This has been used in test accuracy meta-analyses, where empirical knowledge of the test positive rate and the prevalence have been used to derive
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#17327867474992220-402: A fundamental methodology in metascience . Meta-analyses are often, but not always, important components of a systematic review . The term "meta-analysis" was coined in 1976 by the statistician Gene Glass , who stated "Meta-analysis refers to the analysis of analyses" . Glass's work aimed at describing aggregated measures of relationships and effects. While Glass is credited with authoring
2405-511: A further study using the same tests found that prisoners scoring high on the PCL were more likely to endorse impersonal harm or rule violations than non-psychopathic controls were. The psychopathic offenders who scored low in anxiety were also more willing to endorse personal harm on average. Assessing accidents, where one person harmed another unintentionally, psychopaths judged such actions to be more morally permissible. This result has been considered
2590-415: A given dataset, and the mechanism by which the data came into being . A random effect can be present in either of these roles, but the two roles are quite distinct. There's no reason to think the analysis model and data-generation mechanism (model) are similar in form, but many sub-fields of statistics have developed the habit of assuming, for theory and simulations, that the data-generation mechanism (model)
2775-470: A greater influence on happiness levels. Personality is not stable over the course of a lifetime, but it changes much more quickly during childhood, so personality constructs in children are referred to as temperament. Temperament is regarded as the precursor to personality. Another interesting finding has been the link found between acting extraverted and positive affect. Extraverted behaviors include acting talkative, assertive, adventurous, and outgoing. For
2960-524: A meta-analysis are often shown in a forest plot . Results from studies are combined using different approaches. One approach frequently used in meta-analysis in health care research is termed ' inverse variance method '. The average effect size across all studies is computed as a weighted mean , whereby the weights are equal to the inverse variance of each study's effect estimator. Larger studies and studies with less random variation are given greater weight than smaller studies. Other common approaches include
3145-754: A meta-trait associated with mental and physical exploration). There are several personality frameworks that recognize the Big Five factors and there are thousands of measures of personality that can be used to measure specific facets as well as general traits. Some research has investigated whether the relationship between happiness and extraversion seen in adults also can be seen in children. The implications of these findings can help identify children who are more likely to experience episodes of depression and develop types of treatment that such children are likely to respond to. In both children and adults, research shows that genetics, as opposed to environmental factors, exert
3330-537: A narrow and broad sense, such as MedlinePlus from the U.S. National Library of Medicine . On the other hand, Stedman's Medical Dictionary defines "psychopath" only as a "former designation" for a person with an antisocial type of personality disorder. The term psychosis was also used in Germany from 1841, originally in a very general sense. The suffix -ωσις (-osis) meant in this case "abnormal condition". This term or its adjective psychotic would come to refer to
3515-431: A non-existent thing cannot exist. Further, Spinoza's rationalism argued that the mind does not know itself, except insofar as it perceives the "ideas of the modifications of body", in describing its external perceptions, or perceptions from without. On the contrary, from within, Spinoza argued, perceptions connect various ideas clearly and distinctly. The mind is not the free cause of its actions for Spinoza. Spinoza equates
3700-466: A number of the parameters, and the data have to be supplied in a specific format. Together, the DAG, priors, and data form a Bayesian hierarchical model. To complicate matters further, because of the nature of MCMC estimation, overdispersed starting values have to be chosen for a number of independent chains so that convergence can be assessed. Recently, multiple R software packages were developed to simplify
3885-697: A partial constitutional factor that influences its development. Disagreement exists over which features should be considered as part of psychopathy, with researchers identifying around 40 traits supposedly indicative of the construct, though the following characteristics are almost universally considered central. Cooke and Michie (2001) proposed a three-factor model of the Psychopathy Checklist-Revised which has seen widespread application in other measures (e.g., Youth Psychopathic Traits Inventory, Antisocial Process Screening Device). Cleckley's (1941) original description of psychopathy included
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#17327867474994070-498: A philosopher is dissatisfied with any other way of seeing things or not. James argued that temperament may be the basis of several divisions in academia, but focused on philosophy in his 1907 lectures on Pragmatism . In fact, James' lecture of 1907 fashioned a sort of trait theory of the empiricist and rationalist camps of philosophy. As in most modern trait theories, the traits of each camp are described by James as distinct and opposite, and maybe possessed in different proportions on
4255-483: A proportion of their quality adjusted weights is mathematically redistributed to study i giving it more weight towards the overall effect size. As studies become increasingly similar in terms of quality, re-distribution becomes progressively less and ceases when all studies are of equal quality (in the case of equal quality, the quality effects model defaults to the IVhet model – see previous section). A recent evaluation of
4440-558: A reflection of psychopaths' failure to appreciate the emotional aspect of the victim's harmful experience. The word psychopathy is a joining of the Greek words psyche ( ψυχή ) "soul" and pathos ( πάθος ) "suffering, feeling". The first documented use is from 1847 in Germany as psychopatisch , and the noun psychopath has been traced to 1885. In medicine, patho- has a more specific meaning of disease (Thus pathology has meant
4625-548: A region in Receiver Operating Characteristic (ROC) space known as an 'applicable region'. Studies are then selected for the target setting based on comparison with this region and aggregated to produce a summary estimate which is tailored to the target setting. Meta-analysis can also be applied to combine IPD and AD. This is convenient when the researchers who conduct the analysis have their own raw data while collecting aggregate or summary data from
4810-837: A result. In considering the issue of possible reunification of some sex offenders into homes with a non-offending parent and children, it has been advised that any sex offender with a significant criminal history should be assessed on the PCL-R, and if they score 18 or higher, then they should be excluded from any consideration of being placed in a home with children under any circumstances. There is, however, increasing concern that PCL scores are too inconsistent between different examiners, including in its use to evaluate sex offenders. The possibility of psychopathy has been associated with organized crime , economic crime and war crimes . Terrorists are sometimes considered psychopathic, and comparisons may be drawn with traits such as antisocial violence,
4995-700: A sample is more often than not inadequate to accurately estimate heterogeneity . Thus it appears that in small meta-analyses, an incorrect zero between study variance estimate is obtained, leading to a false homogeneity assumption. Overall, it appears that heterogeneity is being consistently underestimated in meta-analyses and sensitivity analyses in which high heterogeneity levels are assumed could be informative. These random effects models and software packages mentioned above relate to study-aggregate meta-analyses and researchers wishing to conduct individual patient data (IPD) meta-analyses need to consider mixed-effects modelling approaches. / Doi and Thalib originally introduced
5180-619: A self-centered disposition, unreliability, poor behavioral controls, and unusual behaviors may disadvantage or preclude psychopathic individuals in conducting organized terrorism. It may be that a significant portion of people with psychopathy are socially successful and tend to express their antisocial behavior through more covert avenues such as social manipulation or white collar crime . Such individuals are sometimes referred to as "successful psychopaths", and may not necessarily always have extensive histories of traditional antisocial behavior as characteristic of traditional psychopathy. The PCL:YV
5365-455: A selfish world view that precludes the welfare of others, a lack of remorse or guilt, and blame externalization. However, John Horgan, author of The Psychology of Terrorism , argues that such comparisons could also then be drawn more widely: for example, to soldiers in wars. Coordinated terrorist activity requires organization, loyalty and ideological fanaticism often to the extreme of sacrificing oneself for an ideological cause. Traits such as
5550-596: A sense of empathy or morality, but sociopathy as only differing from the average person in the sense of right and wrong. Ancient writings that have been connected to psychopathic traits include Deuteronomy 21:18–21 and a description of an unscrupulous man by the Greek philosopher Theophrastus around 300 BC. The concept of psychopathy has been indirectly connected to the early 19th century work of Pinel (1801; "mania without delirium") and Pritchard (1835; " moral insanity "), although historians have largely discredited
5735-492: A shared family environment between siblings has less influence on personality than individual experiences of each child. Identical twins have similar personalities largely because they share the same genetic makeup rather than their shared environment. There has been some recent debate over the subject of studying personality in a different culture. Some people think that personality comes entirely from culture and therefore there can be no meaningful study in cross-culture study. On
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5920-576: A situation similar to publication bias, but their inclusion (assuming null effects) would also bias the meta-analysis. Other weaknesses are that it has not been determined if the statistically most accurate method for combining results is the fixed, IVhet, random or quality effect models, though the criticism against the random effects model is mounting because of the perception that the new random effects (used in meta-analysis) are essentially formal devices to facilitate smoothing or shrinkage and prediction may be impossible or ill-advised. The main problem with
6105-431: A somewhat lower average value of 17.5. Studies have found that psychopathy scores correlated with repeated imprisonment, detention in higher security, disciplinary infractions, and substance misuse. Psychopathy, as measured with the PCL-R in institutional settings, shows in meta-analyses small to moderate effect sizes with institutional misbehavior, postrelease crime, or postrelease violent crime with similar effects for
6290-485: A standardized means of collecting data from eligible studies. For a meta-analysis of correlational data, effect size information is usually collected as Pearson's r statistic. Partial correlations are often reported in research, however, these may inflate relationships in comparison to zero-order correlations. Moreover, the partialed out variables will likely vary from study-to-study. As a consequence, many meta-analyses exclude partial correlations from their analysis. As
6475-541: A sufficiently high variance. The other issue is use of the random effects model in both this frequentist framework and the Bayesian framework. Senn advises analysts to be cautious about interpreting the 'random effects' analysis since only one random effect is allowed for but one could envisage many. Senn goes on to say that it is rather naıve, even in the case where only two treatments are being compared to assume that random-effects analysis accounts for all uncertainty about
6660-406: A test accurate. "Each item should be influenced to a degree by the underlying trait construct, giving rise to a pattern of positive intercorrelations so long as all items are oriented (worded) in the same direction." A recent, but not well-known, measuring tool that psychologists use is the 16PF . It measures personality based on Cattell's 16-factor theory of personality. Psychologists also use it as
6845-453: A weighted average of a series of study estimates. The inverse of the estimates' variance is commonly used as study weight, so that larger studies tend to contribute more than smaller studies to the weighted average. Consequently, when studies within a meta-analysis are dominated by a very large study, the findings from smaller studies are practically ignored. Most importantly, the fixed effects model assumes that all included studies investigate
7030-430: A workaround for multiple arm trials: a different fixed control node can be selected in different runs. It also utilizes robust meta-analysis methods so that many of the problems highlighted above are avoided. Further research around this framework is required to determine if this is indeed superior to the Bayesian or multivariate frequentist frameworks. Researchers willing to try this out have access to this framework through
7215-415: Is heterogeneity this may result in the summary estimate not being representative of individual studies. Qualitative appraisal of the primary studies using established tools can uncover potential biases, but does not quantify the aggregate effect of these biases on the summary estimate. Although the meta-analysis result could be compared with an independent prospective primary study, such external validation
7400-532: Is a categorical difference between psychosis and psychopathy. Socially, psychopathy typically involves extensive callous and manipulative self-serving behaviors with no regard for others, and often is associated with repeated delinquency, crime and violence. Mentally, impairments in processes related to affect and cognition , particularly socially related mental processes, have also been found. Developmentally, symptoms of psychopathy have been identified in young children with conduct disorder , and suggests at least
7585-718: Is a method of synthesis of quantitative data from multiple independent studies addressing a common research question. An important part of this method involves computing a combined effect size across all of the studies. As such, this statistical approach involves extracting effect sizes and variance measures from various studies. By combining these effect sizes the statistical power is improved and can resolve uncertainties or discrepancies found in individual studies. Meta-analyses are integral in supporting research grant proposals, shaping treatment guidelines, and influencing health policies. They are also pivotal in summarizing existing research to guide future studies, thereby cementing their role as
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7770-625: Is a result of the shifts in culture originating in the Renaissance , an essential element in modernity . In contrast, the Medieval European's sense of self was linked to a network of social roles: "the household , the Kinship network, the guild , the corporation – these were the building blocks of personhood". Stephen Greenblatt observes, in recounting the recovery (1417) and career of Lucretius ' poem De rerum natura : "at
7955-409: Is achieved, may also favor statistically significant findings in support of researchers' hypotheses. Studies often do not report the effects when they do not reach statistical significance. For example, they may simply say that the groups did not show statistically significant differences, without reporting any other information (e.g. a statistic or p-value). Exclusion of these studies would lead to
8140-455: Is an adaptation of the PCL-R for individuals aged 13–18 years. It is, like the PCL-R, done by a trained rater based on an interview and an examination of criminal and other records. The "Antisocial Process Screening Device" (APSD) is also an adaptation of the PCL-R. It can be administered by parents or teachers for individuals aged 6–13 years. High psychopathy scores for both juveniles (as measured with these instruments) and adults (as measured with
8325-638: Is an inability to use any energy to make important or difficult decisions, plan for the future, control or regulate emotions, or perform effectively on other cognitive tasks. One question that has been posed is why extraverts tend to be happier than introverts. The two types of explanations that attempt to account for this difference are instrumental theories and temperamental theories. The instrumental theory suggests that extraverts end up making choices that place them in more positive situations and they also react more strongly than introverts to positive situations. The temperamental theory suggests that extroverts have
8510-536: Is argued to be more due to a personality disorder caused by neurological deficits interacting with an adverse environment. For many, but not all, childhood onset is associated with what is in Terrie Moffitt's developmental theory of crime referred to as "life-course- persistent" antisocial behavior as well as poorer health and economic status. Adolescent onset is argued to more typically be associated with short-term antisocial behavior. It has been suggested that
8695-432: Is based on research which suggests that those with conduct disorder who also meet criteria for the specifier tend to have a more severe form of the disorder with an earlier onset as well as a different response to treatment. Proponents of different types/dimensions of psychopathy have seen this as possibly corresponding to adult primary psychopathy and increased boldness and/or meanness in the triarchic model. Dysfunctions in
8880-442: Is dissociable from and not synonymous with violence. It has been suggested that psychopathy is associated with "instrumental aggression", also known as predatory, proactive, or "cold blooded" aggression, a form of aggression characterized by reduced emotion and conducted with a goal differing from but facilitated by the commission of harm. One conclusion in this regard was made by a 2002 study of homicide offenders, which reported that
9065-590: Is evidence from DT-MRI of breakdowns in the white matter connections between these two important areas. Although some studies have suggested inverse relationships between psychopathy and intelligence , including with regards to verbal IQ, Hare and Neumann state that a large literature demonstrates at most only a weak association between psychopathy and IQ , noting that the early pioneer Cleckley included good intelligence in his checklist due to selection bias (since many of his patients were "well educated and from middle-class or upper-class backgrounds") and that "there
9250-405: Is identical to the analysis model we choose (or would like others to choose). As a hypothesized mechanisms for producing the data, the random effect model for meta-analysis is silly and it is more appropriate to think of this model as a superficial description and something we choose as an analytical tool – but this choice for meta-analysis may not work because the study effects are a fixed feature of
9435-483: Is important because much research has been done with single-subject research designs. Considerable dispute exists for the most appropriate meta-analytic technique for single subject research. Meta-analysis leads to a shift of emphasis from single studies to multiple studies. It emphasizes the practical importance of the effect size instead of the statistical significance of individual studies. This shift in thinking has been termed "meta-analytic thinking". The results of
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#17327867474999620-496: Is inefficient and wasteful and that studies are not just wasteful when they stop too late but also when they stop too early. In large clinical trials, planned, sequential analyses are sometimes used if there is considerable expense or potential harm associated with testing participants. In applied behavioural science, "megastudies" have been proposed to investigate the efficacy of many different interventions designed in an interdisciplinary manner by separate teams. One such study used
9805-881: Is necessary to gain stronger support. Culture is an important factor in shaping the personality of individuals. Psychologists have found that cultural norms, beliefs, and practices shape the way people interact and behave with others, which can impact personality development (Cheung et al., 2011). Studies have identified cultural differences in personality traits such as extraversion, agreeableness, and conscientiousness, indicating that culture influences personality development (Allik & McCrae, 2004). For example, Western cultures value individualism, independence, and assertiveness, which are reflected in personality traits such as extraversion. In contrast, Eastern cultures value collectivism, cooperation, and social harmony, which are reflected in personality traits such as agreeableness (Cheung et al., 2011). The modern sense of individual personality
9990-400: Is no obvious theoretical reason why the disorder described by Cleckley or other clinicians should be related to intelligence; some psychopaths are bright, others less so". Studies also indicate that different aspects of the definition of psychopathy (e.g. interpersonal, affective (emotion), behavioral and lifestyle components) can show different links to intelligence, and the result can depend on
10175-492: Is not easily solved, as one cannot know how many studies have gone unreported. This file drawer problem characterized by negative or non-significant results being tucked away in a cabinet, can result in a biased distribution of effect sizes thus creating a serious base rate fallacy , in which the significance of the published studies is overestimated, as other studies were either not submitted for publication or were rejected. This should be seriously considered when interpreting
10360-414: Is not eligible for inclusion, based on the pre-specified criteria. These studies can be discarded. However, if it appears that the study may be eligible (or even if there is some doubt) the full paper can be retained for closer inspection. The references lists of eligible articles can also be searched for any relevant articles. These search results need to be detailed in a PRIMSA flow diagram which details
10545-595: Is not known whether this is reflected in reduced experience of state fear or where it reflects impaired detection and response to threat-related stimuli. Moreover, such deficits in threat responding are known to be reduced or even abolished when attention is focused on the threatening stimuli. In terms of simple correlations, the PCL-R manual states an average score of 22.1 has been found in North American prisoner samples, and that 20.5% scored 30 or higher. An analysis of prisoner samples from outside North America found
10730-419: Is often impractical. This has led to the development of methods that exploit a form of leave-one-out cross validation , sometimes referred to as internal-external cross validation (IOCV). Here each of the k included studies in turn is omitted and compared with the summary estimate derived from aggregating the remaining k- 1 studies. A general validation statistic, Vn based on IOCV has been developed to measure
10915-495: Is one's belief about abilities to perform up to personal standards, the ability to produce desired results, and the feeling of having some ability to make important life decisions. Self-efficacy has been found to be related to the personality traits of extraversion and subjective well-being. Self-efficacy, however, only partially mediates the relationship between extraversion (and neuroticism) and subjective happiness. This implies that there are most likely other factors that mediate
11100-501: Is positive correlation between early negative life events of the ages 0–4 and the emotion-based aspects of psychopathy. There are moderate to high correlations between psychopathy rankings from late childhood to early adolescence. The correlations are considerably lower from early- or mid-adolescence to adulthood. In one study most of the similarities were on the Impulsive- and Antisocial-Behavior scales. Of those adolescents who scored in
11285-404: Is possible. Another issue with the random effects model is that the most commonly used confidence intervals generally do not retain their coverage probability above the specified nominal level and thus substantially underestimate the statistical error and are potentially overconfident in their conclusions. Several fixes have been suggested but the debate continues on. A further concern is that
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#173278674749911470-826: Is present, there would be no relationship between standard error and effect size. A negative or positive relation between standard error and effect size would imply that smaller studies that found effects in one direction only were more likely to be published and/or to be submitted for publication. Apart from the visual funnel plot, statistical methods for detecting publication bias have also been proposed. These are controversial because they typically have low power for detection of bias, but also may make false positives under some circumstances. For instance small study effects (biased smaller studies), wherein methodological differences between smaller and larger studies exist, may cause asymmetry in effect sizes that resembles publication bias. However, small study effects may be just as problematic for
11655-399: Is referred to) as psychopathy or sociopathy . The creation of ASPD and DPD was driven by the fact that many of the classic traits of psychopathy were impossible to measure objectively. Canadian psychologist Robert D. Hare later re-popularized the construct of psychopathy in criminology with his Psychopathy Checklist . Although no psychiatric or psychological organization has sanctioned
11840-474: Is reported that offenders with psychopathy (both sexual and non-sexual offenders) are about 2.5 times more likely to be granted conditional release compared to non-psychopathic offenders. Hildebrand and colleagues (2004) have uncovered an interaction between psychopathy and deviant sexual interests , wherein those high in psychopathy who also endorsed deviant sexual interests were more likely to recidivate sexually. A subsequent meta-analysis has consolidated such
12025-493: Is solely dependent on two factors: Since neither of these factors automatically indicates a faulty larger study or more reliable smaller studies, the re-distribution of weights under this model will not bear a relationship to what these studies actually might offer. Indeed, it has been demonstrated that redistribution of weights is simply in one direction from larger to smaller studies as heterogeneity increases until eventually all studies have equal weight and no more redistribution
12210-577: Is the Bucher method which is a single or repeated comparison of a closed loop of three-treatments such that one of them is common to the two studies and forms the node where the loop begins and ends. Therefore, multiple two-by-two comparisons (3-treatment loops) are needed to compare multiple treatments. This methodology requires that trials with more than two arms have two arms only selected as independent pair-wise comparisons are required. The alternative methodology uses complex statistical modelling to include
12395-533: Is the ability to maintain one's average level of happiness in the face of an ambiguous situation – meaning a situation that has the potential to engender either positive or negative emotions in different individuals. It has been found to be a stronger force in extroverts. This means that the happiness levels of extraverted individuals are less susceptible to the influence of external events. This finding implies that extraverts' positive moods last longer than those of introverts. Modern conceptions of personality, such as
12580-570: Is usually unattainable in practice. There are many methods used to estimate between studies variance with restricted maximum likelihood estimator being the least prone to bias and one of the most commonly used. Several advanced iterative techniques for computing the between studies variance exist including both maximum likelihood and restricted maximum likelihood methods and random effects models using these methods can be run with multiple software platforms including Excel, Stata, SPSS, and R. Most meta-analyses include between 2 and 4 studies and such
12765-514: Is usually unavailable. Great claims are sometimes made for the inherent ability of the Bayesian framework to handle network meta-analysis and its greater flexibility. However, this choice of implementation of framework for inference, Bayesian or frequentist, may be less important than other choices regarding the modeling of effects (see discussion on models above). On the other hand, the frequentist multivariate methods involve approximations and assumptions that are not stated explicitly or verified when
12950-440: Is whether to include studies from the gray literature, which is defined as research that has not been formally published. This type of literature includes conference abstracts, dissertations, and pre-prints. While the inclusion of gray literature reduces the risk of publication bias, the methodological quality of the work is often (but not always) lower than formally published work. Reports from conference proceedings, which are
13135-401: The y i {\displaystyle y_{i}} ’s are assumed to be unbiased and normally distributed estimates of their corresponding true effects. The sampling variances (i.e., v i {\displaystyle v_{i}} values) are assumed to be known. Most meta-analyses are based on sets of studies that are not exactly identical in their methods and/or
13320-579: The Cochrane Database of Systematic Reviews . The 29 meta-analyses reviewed a total of 509 randomized controlled trials (RCTs). Of these, 318 RCTs reported funding sources, with 219 (69%) receiving funding from industry (i.e. one or more authors having financial ties to the pharmaceutical industry). Of the 509 RCTs, 132 reported author conflict of interest disclosures, with 91 studies (69%) disclosing one or more authors having financial ties to industry. The information was, however, seldom reflected in
13505-660: The Mantel–Haenszel method and the Peto method . Seed-based d mapping (formerly signed differential mapping, SDM) is a statistical technique for meta-analyzing studies on differences in brain activity or structure which used neuroimaging techniques such as fMRI, VBM or PET. Different high throughput techniques such as microarrays have been used to understand Gene expression . MicroRNA expression profiles have been used to identify differentially expressed microRNAs in particular cell or tissue type or disease conditions or to check
13690-489: The Office of Strategic Services in 1943, and which may have been intended to be used as propaganda , non-medical psychoanalyst Walter C. Langer suggested Adolf Hitler was probably a psychopath . However, others have not drawn this conclusion; clinical forensic psychologist Glenn Walters argues that Hitler's actions do not warrant a diagnosis of psychopathy as, although he showed several characteristics of criminality, he
13875-687: The Psychopathic Personality Inventory , known as Fearless Dominance. To some, it is evidence of psychopathy not being a more extreme version of ASPD, but as an emergent compound trait that manifests when Antisocial Personality Disorder is present in combination with high levels of Fearless Dominance (or Boldness as it's known in the Triarchic Model). Analyses showed that this Section III ASPD greatly outperformed Section II ASPD in predicting scores on Hare’s (2003) Psychopathy Checklist-Revised. Section III ASPD including
14060-473: The Temperament and Character Inventory have suggested four basic temperaments that are thought to reflect basic and automatic responses to danger and reward that rely on associative learning. The four temperaments, harm avoidance , reward dependence , novelty-seeking and persistence , are somewhat analogous to ancient conceptions of melancholic, sanguine, choleric, phlegmatic personality types, although
14245-543: The construct of psychopathy does not necessarily add value to violence risk assessment . A large systematic review and meta-regression found that the PCL performed the poorest out of nine tools for predicting violence. In addition, studies conducted by the authors or translators of violence prediction measures, including the PCL, show on average more positive results than those conducted by more independent investigators. There are several other risk assessment instruments which can predict further crime with an accuracy similar to
14430-806: The prefrontal cortex and amygdala regions of the brain have been associated with specific learning impairments in psychopathy. Damage to the ventromedial prefrontal cortex, which regulates the activity in the amygdala, leads to common characteristics in psychopathic individuals. Since the 1980s, scientists have linked traumatic brain injury , including damage to these regions, with violent and psychopathic behavior. Patients with damage in such areas resembled "psychopathic individuals" whose brains were incapable of acquiring social and moral knowledge; those who acquired damage as children may have trouble conceptualizing social or moral reasoning, while those with adult-acquired damage may be aware of proper social and moral conduct but be unable to behave appropriately. Dysfunctions in
14615-613: The 'Psychopathic Traits Specifier' can be seen on page 765 of the DSM-5 or Page 885 of the DSM-5-TR. The term is used in various ways in contemporary usage. Robert Hare stated in the popular science book Snakes in Suits that sociopathy and psychopathy are often used interchangeably, but in some cases the term sociopathy is preferred because it is less likely than is psychopathy to be confused with psychosis , whereas in other cases
14800-814: The 1960s. Many factor analyses found what is called the Big Five , which are openness to experience , conscientiousness , extraversion , agreeableness , and neuroticism (or emotional stability), known as "OCEAN". These components are generally stable over time, and about half of the variance appears to be attributable to a person's genetics rather than the effects of one's environment. These five factors are made up of two aspects each as well as many facets (e.g., openness splits into experiencing and intellect, which each further split into facets like fantasy and ideas). These five factors also show correlations with each other that suggest higher order meta-traits (e.g., factor beta, which combines openness and extraversion to form
14985-606: The Affective facet of the PCL-R predicted reduced offense seriousness. Studies on perpetrators of domestic violence find that abusers have high rates of psychopathy, with the prevalence estimated to be at around 15-30%. Furthermore, the commission of domestic violence is correlated with Factor 1 of the PCL-R , which describes the emotional deficits and the callous and exploitative interpersonal style found in psychopathy. The prevalence of psychopathy among domestic abusers indicate that
15170-525: The NEO-PI-R to 7,134 people across six languages, the results show a similar pattern of the same five underlying constructs that are found in the American factor structure. Similar results were found using the Big Five Inventory (BFI), as it was administered in 56 nations across 28 languages. The five factors continued to be supported both conceptually and statistically across major regions of
15355-512: The PCL-R and Fearless dominance of the PPI-R have smaller or no relationship to crime, including violent crime. In contrast, Factor 2 and Impulsive antisociality of the PPI-R are associated more strongly with criminality. Factor 2 has a relationship of similar strength to that of the PCL-R as a whole. The antisocial facet of the PCL-R is still predictive of future violence after controlling for past criminal behavior which, together with results regarding
15540-417: The PCL-R and other measurement tools) have similar associations with other variables, including similar ability in predicting violence and criminality. Juvenile psychopathy may also be associated with more negative emotionality such as anger, hostility, anxiety, and depression. Psychopathic traits in youth typically comprise three factors: callous/unemotional, narcissism, and impulsivity/irresponsibility. There
15725-536: The PCL-R and some of these are considerably easier, quicker, and less expensive to administer. This may even be done automatically by a computer simply based on data such as age, gender, number of previous convictions and age of first conviction. Some of these assessments may also identify treatment change and goals, identify quick changes that may help short-term management, identify more specific kinds of violence that may be at risk, and may have established specific probabilities of offending for specific scores. Nonetheless,
15910-432: The PCL-R may continue to be popular for risk assessment because of its pioneering role and the large amount of research done using it. The U.S. Federal Bureau of Investigation (FBI) reports that psychopathic behavior is consistent with traits common to some serial killers , including sensation seeking, a lack of remorse or guilt , impulsivity , the need for control , and predatory behavior. It has also been found that
16095-462: The PPI-R which by design does not include past criminal behavior, suggests that impulsive behaviors is an independent risk factor. Thus, the concept of psychopathy may perform poorly when attempted to be used as a general theory of crime. Studies have suggested a strong correlation between psychopathy scores and violence , and the PCL-R emphasizes features that are somewhat predictive of violent behavior. Researchers, however, have noted that psychopathy
16280-592: The United States Environmental Protection Agency had abused the meta-analysis process to produce a study claiming cancer risks to non-smokers from environmental tobacco smoke (ETS) with the intent to influence policy makers to pass smoke-free–workplace laws. Meta-analysis may often not be a substitute for an adequately powered primary study, particularly in the biological sciences. Heterogeneity of methods used may lead to faulty conclusions. For instance, differences in
16465-493: The absence of nervousness and neurotic disorders, and later theorists referred to psychopaths as fearless or thick-skinned. While it is often claimed that the PCL-R does not include low anxiety or fearlessness, such features do contribute to the scoring of the Facet 1 (interpersonal) items, mainly through self-assurance, unrealistic optimism, brazenness and imperturbability. Indeed, while self-report studies have been inconsistent using
16650-544: The active faculty produces and forms ideas, but does not presuppose thought, and thus cannot be within the thinking thing. The active faculty mustn't be within self because ideas are produced without any awareness of them, and are sometimes produced against one's will. Rationalist philosopher Benedictus Spinoza (1632–1677) argued that ideas are the first element constituting the human mind, but existed only for actually existing things. In other words, ideas of non-existent things are without meaning for Spinoza, because an idea of
16835-416: The amygdala and ventromedial prefrontal cortex may also impair stimulus-reinforced learning in psychopaths, whether punishment-based or reward-based. People scoring 25 or higher in the PCL-R, with an associated history of violent behavior, appear to have significantly reduced mean microstructural integrity in their uncinate fasciculus — white matter connecting the amygdala and orbitofrontal cortex . There
17020-425: The author's agenda are likely to have their studies cherry-picked while those not favorable will be ignored or labeled as "not credible". In addition, the favored authors may themselves be biased or paid to produce results that support their overall political, social, or economic goals in ways such as selecting small favorable data sets and not incorporating larger unfavorable data sets. The influence of such biases on
17205-564: The average treatment effect can sometimes be even less conservative compared to the fixed effect model and therefore misleading in practice. One interpretational fix that has been suggested is to create a prediction interval around the random effects estimate to portray the range of possible effects in practice. However, an assumption behind the calculation of such a prediction interval is that trials are considered more or less homogeneous entities and that included patient populations and comparator treatments should be considered exchangeable and this
17390-513: The basis of human traits rather than within certain cultures. This can be measured by comparing whether assessment tools are measuring similar constructs across countries or cultures. Two approaches to researching personality are looking at emic and etic traits. Emic traits are constructs unique to each culture, which are determined by local customs, thoughts, beliefs, and characteristics. Etic traits are considered universal constructs, which establish traits that are evident across cultures that represent
17575-466: The basis of temperament. Furthermore, such categorization was only incidental to James' purpose of explaining his pragmatist philosophy and is not exhaustive. According to James, the temperament of rationalist philosophers differed fundamentally from the temperament of empiricist philosophers of his day. The tendency of rationalist philosophers toward refinement and superficiality never satisfied an empiricist temper of mind. Rationalism leads to
17760-488: The brain relates to various psychological processes and behaviors. For instance, in human beings, the frontal lobes are responsible for foresight and anticipation, and the occipital lobes are responsible for processing visual information. In addition, certain physiological functions such as hormone secretion also affect personality. For example, the hormone testosterone is important for sociability, affectivity, aggressiveness , and sexuality. Additionally, studies show that
17945-996: The brain. Research has also shown that an approximate 18% smaller amygdala size contributes to a significantly lower emotional sensation in regards to fear, sadness, amongst other negative emotions, which may likely be the reason as to why psychopathic individuals have lower empathy. Some recent fMRI studies have reported that emotion perception deficits in psychopathy are pervasive across emotions (positives and negatives). Studies on children with psychopathic tendencies have also shown such associations. Meta-analyses have also found evidence of impairments in both vocal and facial emotional recognition for several emotions (i.e., not only fear and sadness) in both adults and children/adolescents. Psychopathy has been associated with amorality —an absence of, indifference towards, or disregard for moral beliefs. There are few firm data on patterns of moral judgment. Studies of developmental level (sophistication) of moral reasoning found all possible results—lower, higher or
18130-466: The characteristics of the included samples. Differences in the methods and sample characteristics may introduce variability (“heterogeneity”) among the true effects. One way to model the heterogeneity is to treat it as purely random. The weight that is applied in this process of weighted averaging with a random effects meta-analysis is achieved in two steps: This means that the greater this variability in effect sizes (otherwise known as heterogeneity ),
18315-577: The clustering of participants within studies. Two-stage methods first compute summary statistics for AD from each study and then calculate overall statistics as a weighted average of the study statistics. By reducing IPD to AD, two-stage methods can also be applied when IPD is available; this makes them an appealing choice when performing a meta-analysis. Although it is conventionally believed that one-stage and two-stage methods yield similar results, recent studies have shown that they may occasionally lead to different conclusions. The fixed effect model provides
18500-590: The combination of early-onset conduct disorder and ADHD may be associated with life-course-persistent antisocial behaviors as well as psychopathy. There is evidence that this combination is more aggressive and antisocial than those with conduct disorder alone. However, it is not a particularly distinct group since the vast majority of young children with conduct disorder also have ADHD. Some evidence indicates that this group has deficits in behavioral inhibition, similar to that of adults with psychopathy. They may not be more likely than those with conduct disorder alone to have
18685-415: The concept of psychopathy . It was used to indicate that the defining feature is violation of social norms , or antisocial behavior, and may be social or biological in origin. The terms sociopathy and psychopathy were once used interchangeably in relation to antisocial personality disorder , though this usage is outdated in medicine and psychiatry. Psychopathy, however, is a highly popular construct in
18870-526: The core characteristics of psychopathy, such as callousness, remorselessness, and a lack of close interpersonal bonds, predispose those with psychopathy to committing domestic abuse, and suggest that the domestic abuses committed by these individuals are callously perpetrated (i.e. instrumentally aggressive) rather than a case of emotional aggression and therefore may not be amenable to the types of psychosocial interventions commonly given to domestic abuse perpetrators. Some clinicians suggest that assessment of
19055-402: The core of the poem lay key principles of a modern understanding of the world." "Dependent on the family, the individual alone was nothing," Jacques Gélis observes. "The characteristic mark of the modern man has two parts: one internal, the other external; one dealing with his environment, the other with his attitudes, values, and feelings." Rather than being linked to a network of social roles,
19240-451: The creation of closed systems , and such optimism is considered shallow by the fact-loving mind, for whom perfection is far off. Rationalism is regarded as pretension , and a temperament most inclined to abstraction . Empiricists , on the other hand, stick with the external senses rather than logic. British empiricist John Locke 's (1632–1704) explanation of personal identity provides an example of what James referred to. Locke explains
19425-423: The creation of software tools across disciplines. One of the most important steps of a meta-analysis is data collection. For an efficient database search, appropriate keywords and search limits need to be identified. The use of Boolean operators and search limits can assist the literature search. A number of databases are available (e.g., PubMed, Embase, PsychInfo), however, it is up to the researcher to choose
19610-415: The damaging gap which has opened up between methodology and statistics in clinical research. To do this a synthetic bias variance is computed based on quality information to adjust inverse variance weights and the quality adjusted weight of the i th study is introduced. These adjusted weights are then used in meta-analysis. In other words, if study i is of good quality and other studies are of poor quality,
19795-523: The diagnosis. The diagnostic category of sociopathic personality in early editions of the Diagnostic and Statistical Manual (DSM) had some key similarities to Cleckley's ideas, though in 1980 when renamed Antisocial Personality Disorder some of the underlying personality assumptions were removed. In 1980, Canadian psychologist Robert D. Hare introduced an alternative measure, the " Psychopathy Checklist " (PCL) based largely on Cleckley's criteria, which
19980-492: The effect size. However, others have argued that a better approach is to preserve information about the variance in the study sample, casting as wide a net as possible, and that methodological selection criteria introduce unwanted subjectivity, defeating the purpose of the approach. More recently, and under the influence of a push for open practices in science, tools to develop "crowd-sourced" living meta-analyses that are updated by communities of scientists in hopes of making all
20165-399: The effect sizes of a set of studies using a weighted average. It can test if the outcomes of studies show more variation than the variation that is expected because of the sampling of different numbers of research participants. Additionally, study characteristics such as measurement instrument used, population sampled, or aspects of the studies' design can be coded and used to reduce variance of
20350-488: The effects of A vs B in an indirect comparison as effect A vs Placebo minus effect B vs Placebo. IPD evidence represents raw data as collected by the study centers. This distinction has raised the need for different meta-analytic methods when evidence synthesis is desired, and has led to the development of one-stage and two-stage methods. In one-stage methods the IPD from all studies are modeled simultaneously whilst accounting for
20535-564: The equating of this to mean exclusively "in cold blood", more than a third of the homicides committed by psychopathic offenders involved some component of emotional reactivity as well. In any case, FBI profilers indicate that serious victim injury is generally an emotional offense, and some research supports this, at least with regard to sexual offending. One study has found more serious offending by non-psychopathic offenders on average than by offenders with psychopathy (e.g. more homicides versus more armed robbery and property offenses) and another that
20720-527: The estimator (see statistical models above). Thus some methodological weaknesses in studies can be corrected statistically. Other uses of meta-analytic methods include the development and validation of clinical prediction models, where meta-analysis may be used to combine individual participant data from different research centers and to assess the model's generalisability, or even to aggregate existing prediction models. Meta-analysis can be done with single-subject design as well as group research designs. This
20905-446: The expression of a personality trait depends on the volume of the brain cortex it is associated with. Personology confers a multidimensional, complex, and comprehensive approach to personality. According to Henry A. Murray , personology is: The branch of psychology which concerns itself with the study of human lives and the factors that influence their course which investigates individual differences and types of personality ...
21090-535: The first modern meta-analysis, a paper published in 1904 by the statistician Karl Pearson in the British Medical Journal collated data from several studies of typhoid inoculation and is seen as the first time a meta-analytic approach was used to aggregate the outcomes of multiple clinical studies. Numerous other examples of early meta-analyses can be found including occupational aptitude testing, and agriculture. The first model meta-analysis
21275-469: The flow of information through all stages of the review. Thus, it is important to note how many studies were returned after using the specified search terms and how many of these studies were discarded, and for what reason. The search terms and strategy should be specific enough for a reader to reproduce the search. The date range of studies, along with the date (or date period) the search was conducted should also be provided. A data collection form provides
21460-692: The forms of an intervention or the cohorts that are thought to be minor or are unknown to the scientists could lead to substantially different results, including results that distort the meta-analysis' results or are not adequately considered in its data. Vice versa, results from meta-analyses may also make certain hypothesis or interventions seem nonviable and preempt further research or approvals, despite certain modifications – such as intermittent administration, personalized criteria and combination measures – leading to substantially different results, including in cases where such have been successfully identified and applied in small-scale studies that were considered in
21645-445: The greater the un-weighting and this can reach a point when the random effects meta-analysis result becomes simply the un-weighted average effect size across the studies. At the other extreme, when all effect sizes are similar (or variability does not exceed sampling error), no REVC is applied and the random effects meta-analysis defaults to simply a fixed effect meta-analysis (only inverse variance weighting). The extent of this reversal
21830-439: The homicide victims of psychopathic offenders were disproportionately female in comparison to the more equitable gender distribution of victims of non-psychopathic offenders. Psychopathy has been associated with commission of sexual crime , with some researchers arguing that it is correlated with a preference for violent sexual behavior. A 2011 study of conditional releases for Canadian male federal offenders found that psychopathy
22015-472: The homicides committed by homicidal offenders with psychopathy were almost always (93.3%) primarily instrumental, significantly more than the proportion (48.4%) of those committed by non-psychopathic homicidal offenders, with the instrumentality of the homicide also correlated with the total PCL-R score of the offender as well as their scores on the Factor 1 "interpersonal-affective" dimension. However, contrary to
22200-613: The idea of a direct equivalence. Psychopathy originally described any illness of the mind, but found its application to a narrow subset of mental conditions when it was used toward the end of the 19th century by the German psychiatrist Julius Koch (1891) to describe various behavioral and moral dysfunction in the absence of an obvious mental illness or intellectual disability . He applied the term psychopathic inferiority ( psychopathischen Minderwertigkeiten ) to various chronic conditions and character disorders, and his work would influence
22385-527: The identity of a person, i.e. personality, on the basis of a precise definition of identity, by which the meaning of identity differs according to what it is being applied to. The identity of a person is quite distinct from the identity of a man, woman, or substance according to Locke. Locke concludes that consciousness is personality because it "always accompanies thinking, it is that which makes everyone to be what he calls self," and remains constant in different places at different times. Rationalists conceived of
22570-519: The identity of persons differently than empiricists such as Locke who distinguished identity of substance, person, and life. According to Locke, René Descartes (1596–1650) agreed only insofar as he did not argue that one immaterial spirit is the basis of the person "for fear of making brutes thinking things too." According to James, Locke tolerated arguments that a soul was behind the consciousness of any person. However, Locke's successor David Hume (1711–1776), and empirical psychologists after him denied
22755-812: The influence of the first theorists in the field, a group that includes Sigmund Freud , Alfred Adler , Gordon Allport , Hans Eysenck , Abraham Maslow , and Carl Rogers . Personality can be determined through a variety of tests. Due to the fact that personality is a complex idea, the dimensions of personality and scales of such tests vary and often are poorly defined. Two main tools to measure personality are objective tests and projective measures. Examples of such tests are the: Big Five Inventory (BFI), Minnesota Multiphasic Personality Inventory (MMPI-2), Rorschach Inkblot test , Neurotic Personality Questionnaire KON-2006 , or Eysenck's Personality Questionnaire (EPQ-R). All of these tests are beneficial because they have both reliability and validity , two factors that make
22940-532: The initial diagnostic criteria for antisocial personality reaction/disturbance in the Diagnostic and Statistical Manual of Mental Disorders (DSM), as did American psychologist George E. Partridge . The DSM and International Classification of Diseases (ICD) subsequently introduced the diagnoses of antisocial personality disorder (ASPD) and dissocial personality disorder (DPD) respectively, stating that these diagnoses have been referred to (or include what
23125-492: The interpersonal/affective features and the deficits in emotional processing characteristic of adults with psychopathy. Proponents of different types/dimensions of psychopathy have seen this type as possibly corresponding to adult secondary psychopathy and increased disinhibition in the triarchic model. The DSM-5 includes a specifier for those with conduct disorder who also display a callous, unemotional interpersonal style across multiple settings and relationships. The specifier
23310-704: The interpretation of meta-analyses, and the imperative is on meta-analytic authors to investigate potential sources of bias. The problem of publication bias is not trivial as it is suggested that 25% of meta-analyses in the psychological sciences may have suffered from publication bias. However, low power of existing tests and problems with the visual appearance of the funnel plot remain an issue, and estimates of publication bias may remain lower than what truly exists. Most discussions of publication bias focus on journal practices favoring publication of statistically significant findings. However, questionable research practices, such as reworking statistical models until significance
23495-505: The later conception of the personality disorder. The term psychopathic came to be used to describe a diverse range of dysfunctional or antisocial behavior and mental and sexual deviances, including at the time homosexuality . It was often used to imply an underlying "constitutional" or genetic origin. Disparate early descriptions likely set the stage for modern controversies about the definition of psychopathy. An influential figure in shaping modern American conceptualizations of psychopathy
23680-514: The literature) and typically represents summary estimates such as odds ratios or relative risks. This can be directly synthesized across conceptually similar studies using several approaches. On the other hand, indirect aggregate data measures the effect of two treatments that were each compared against a similar control group in a meta-analysis. For example, if treatment A and treatment B were directly compared vs placebo in separate meta-analyses, we can use these two pooled results to get an estimate of
23865-427: The literature. The generalized integration model (GIM) is a generalization of the meta-analysis. It allows that the model fitted on the individual participant data (IPD) is different from the ones used to compute the aggregate data (AD). GIM can be viewed as a model calibration method for integrating information with more flexibility. The meta-analysis estimate represents a weighted average across studies and when there
24050-405: The meta-analyses. Only two (7%) reported RCT funding sources and none reported RCT author-industry ties. The authors concluded "without acknowledgment of COI due to industry funding or author industry financial ties from RCTs included in meta-analyses, readers' understanding and appraisal of the evidence from the meta-analysis may be compromised." For example, in 1998, a US federal judge found that
24235-424: The meta-analysis. Standardization , reproduction of experiments , open data and open protocols may often not mitigate such problems, for instance as relevant factors and criteria could be unknown or not be recorded. There is a debate about the appropriate balance between testing with as few animals or humans as possible and the need to obtain robust, reliable findings. It has been argued that unreliable research
24420-428: The method: a good meta-analysis cannot correct for poor design or bias in the original studies. This would mean that only methodologically sound studies should be included in a meta-analysis, a practice called 'best evidence synthesis'. Other meta-analysts would include weaker studies, and add a study-level predictor variable that reflects the methodological quality of the studies to examine the effect of study quality on
24605-462: The methodological quality of the studies they include. For example, studies that include small samples or researcher-made measures lead to inflated effect size estimates. However, this problem also troubles meta-analysis of clinical trials. The use of different quality assessment tools (QATs) lead to including different studies and obtaining conflicting estimates of average treatment effects. Modern statistical meta-analysis does more than just combine
24790-399: The methods are applied (see discussion on meta-analysis models above). For example, the mvmeta package for Stata enables network meta-analysis in a frequentist framework. However, if there is no common comparator in the network, then this has to be handled by augmenting the dataset with fictional arms with high variance, which is not very objective and requires a decision as to what constitutes
24975-429: The model fitting (e.g., metaBMA and RoBMA ) and even implemented in statistical software with graphical user interface ( GUI ): JASP . Although the complexity of the Bayesian approach limits usage of this methodology, recent tutorial papers are trying to increase accessibility of the methods. Methodology for automation of this method has been suggested but requires that arm-level outcome data are available, and this
25160-449: The modern man is largely influenced by the environmental factors such as: "urbanization, education, mass communication, industrialization, and politicization." William James (1842–1910) argued that temperament explains a great deal of the controversies in the history of philosophy by arguing that it is a very influential premise in the arguments of philosophers. Despite seeking only impersonal reasons for their conclusions, James argued,
25345-439: The more severe mental disturbances and then specifically to mental states or disorders characterized by hallucinations , delusions or in some other sense markedly out of touch with reality . The slang term psycho has been traced to a shortening of the adjective psychopathic from 1936, and from 1942 as a shortening of the noun psychopath , but it is also used as shorthand for psychotic or crazed. The media usually uses
25530-404: The most appropriate sources for their research area. Indeed, many scientists use duplicate search terms within two or more databases to cover multiple sources. The reference lists of eligible studies can also be searched for eligible studies (i.e., snowballing). The initial search may return a large volume of studies. Quite often, the abstract or the title of the manuscript reveals that the study
25715-431: The most common source of gray literature, are poorly reported and data in the subsequent publication is often inconsistent, with differences observed in almost 20% of published studies. In general, two types of evidence can be distinguished when performing a meta-analysis: individual participant data (IPD), and aggregate data (AD). The aggregate data can be direct or indirect. AD is more commonly available (e.g. from
25900-495: The multiple arm trials and comparisons simultaneously between all competing treatments. These have been executed using Bayesian methods, mixed linear models and meta-regression approaches. Specifying a Bayesian network meta-analysis model involves writing a directed acyclic graph (DAG) model for general-purpose Markov chain Monte Carlo (MCMC) software such as WinBUGS. In addition, prior distributions have to be specified for
26085-442: The observed effect in the i {\displaystyle i} -th study, θ i {\displaystyle \theta _{i}} the corresponding (unknown) true effect, e i {\displaystyle e_{i}} is the sampling error, and e i ∼ N ( 0 , v i ) {\displaystyle e_{i}\thicksim N(0,v_{i})} . Therefore,
26270-787: The occurrence of life experiences. One study has shown how the home environment, specifically the types of parents a person has, can affect and shape their personality. Mary Ainsworth's strange situation experiment showcased how babies reacted to having their mother leave them alone in a room with a stranger. The different styles of attachment, labeled by Ainsworth, were Secure, Ambivalent, avoidant, and disorganized. Children who were securely attached tend to be more trusting, sociable, and are confident in their day-to-day life. Children who were disorganized were reported to have higher levels of anxiety, anger, and risk-taking behavior. Judith Rich Harris 's group socialization theory postulates that an individual's peer groups, rather than parental figures, are
26455-417: The other hand, many believe that some elements are shared by all cultures and an effort is being made to demonstrate the cross-cultural applicability of "the Big Five". Cross-cultural assessment depends on the universality of personality traits, which is whether there are common traits among humans regardless of culture or other factors. If there is a common foundation of personality, then it can be studied on
26640-587: The other hand, more behaviorally-based approaches define personality through learning and habits . Nevertheless, most theories view personality as relatively stable. The study of the psychology of personality, called personality psychology , attempts to explain the tendencies that underlie differences in behavior. Psychologists have taken many different approaches to the study of personality, including biological, cognitive, learning, and trait-based theories, as well as psychodynamic, and humanistic approaches. The various approaches used to study personality today reflect
26825-402: The outcomes of a meta-analysis. The distribution of effect sizes can be visualized with a funnel plot which (in its most common version) is a scatter plot of standard error versus the effect size. It makes use of the fact that the smaller studies (thus larger standard errors) have more scatter of the magnitude of effect (being less precise) while the larger studies have less scatter and form
27010-585: The parental style or home environment. Tessuya Kawamoto's Personality Change from Life Experiences: Moderation Effect of Attachment Security talked about some significant laboratory tests. The study mainly focused on the effects of life experiences on change in personality and life experiences. The assessments suggested that "the accumulation of small daily experiences may work for the personality development of university students and that environmental influences may vary by individual susceptibility to experiences, like attachment security". Some studies suggest that
27195-409: The phenomenon of ego depletion. Ego depletion , or cognitive fatigue, is the use of one's energy to overtly act in a way that is contrary to one's inner disposition. When people act in a contrary fashion, they divert most, if not all, (cognitive) energy toward regulating this foreign style of behavior and attitudes. Because all available energy is being used to maintain this contrary behavior, the result
27380-404: The primary influence of personality and behavior in adulthood. Intra- and intergroup processes, not dyadic relationships such as parent-child relationships, are responsible for the transmission of culture and for environmental modification of children's personality characteristics. Thus, this theory points at the peer group representing the environmental influence on a child's personality rather than
27565-509: The psychology literature. Furthermore, the DSM-5 introduced the dimensional model of personality disorders in Section III, which includes a specifier for psychopathic traits. According to the DSM, psychopathy is not a standalone diagnosis, but the authors attempted to measure "psychopathic traits" via a specifier. In one study, the "Psychopathic Features Specifier" has been modeled on Factor 1 of
27750-576: The purposes of this study, positive affect is defined as experiences of happy and enjoyable emotions. This study investigated the effects of acting in a way that is counter to a person's dispositional nature. In other words, the study focused on the benefits and drawbacks of introverts (people who are shy, socially inhibited, and non-aggressive) acting extraverted, and of extraverts acting introverted. After acting extraverted, introverts' experience of positive affect increased whereas extraverts seemed to experience lower levels of positive affect and suffered from
27935-464: The quality and risk of bias in observational studies reflecting the diversity of research approaches between fields. These tools usually include an assessment of how dependent variables were measured, appropriate selection of participants, and appropriate control for confounding factors. Other quality measures that may be more relevant for correlational studies include sample size, psychometric properties, and reporting of methods. A final consideration
28120-573: The quality effects model (with some updates) demonstrates that despite the subjectivity of quality assessment, the performance (MSE and true variance under simulation) is superior to that achievable with the random effects model. This model thus replaces the untenable interpretations that abound in the literature and a software is available to explore this method further. Indirect comparison meta-analysis methods (also called network meta-analyses, in particular when multiple treatments are assessed simultaneously) generally use two main methodologies. First,
28305-511: The quality effects model. They introduced a new approach to adjustment for inter-study variability by incorporating the contribution of variance due to a relevant component (quality) in addition to the contribution of variance due to random error that is used in any fixed effects meta-analysis model to generate weights for each study. The strength of the quality effects meta-analysis is that it allows available methodological evidence to be used over subjective random effects, and thereby helps to close
28490-411: The random effects approach is that it uses the classic statistical thought of generating a "compromise estimator" that makes the weights close to the naturally weighted estimator if heterogeneity across studies is large but close to the inverse variance weighted estimator if the between study heterogeneity is small. However, what has been ignored is the distinction between the model we choose to analyze
28675-407: The relationship between subjective happiness and personality traits. Self-esteem maybe another similar factor. Individuals with a greater degree of confidence about themselves and their abilities seem to have both higher degrees of subjective well-being and higher levels of extraversion. Other research has examined the phenomenon of mood maintenance as another possible mediator. Mood maintenance
28860-435: The respective meta-analysis and the probability distribution is only a descriptive tool. The most severe fault in meta-analysis often occurs when the person or persons doing the meta-analysis have an economic , social , or political agenda such as the passage or defeat of legislation . People with these types of agendas may be more likely to abuse meta-analysis due to personal bias . For example, researchers favorable to
29045-479: The results of a meta-analysis is possible because the methodology of meta-analysis is highly malleable. A 2011 study done to disclose possible conflicts of interests in underlying research studies used for medical meta-analyses reviewed 29 meta-analyses and found that conflicts of interests in the studies underlying the meta-analyses were rarely disclosed. The 29 meta-analyses included 11 from general medicine journals, 15 from specialty medicine journals, and three from
29230-518: The same as non-psychopaths. Studies that compared judgments of personal moral transgressions versus judgments of breaking conventional rules or laws found that psychopaths rated them as equally severe, whereas non-psychopaths rated the rule-breaking as less severe. A study comparing judgments of whether personal or impersonal harm would be endorsed in order to achieve the rationally maximum ( utilitarian ) amount of welfare found no significant differences between subjects high and low in psychopathy. However,
29415-620: The same population, use the same variable and outcome definitions, etc. This assumption is typically unrealistic as research is often prone to several sources of heterogeneity . If we start with a collection of independent effect size estimates, each estimate a corresponding effect size i = 1 , … , k {\displaystyle i=1,\ldots ,k} we can assume that y i = θ i + e i {\textstyle y_{i}=\theta _{i}+e_{i}} where y i {\displaystyle y_{i}} denotes
29600-463: The science of men, taken as gross units ... encompassing " psychoanalysis " ( Freud ), " analytical psychology " ( Jung ), " individual psychology " ( Adler ) and other terms that stand for methods of inquiry or doctrines rather than realms of knowledge. From a holistic perspective, personology studies personality as a whole, as a system, but at the same time through all its components, levels, and spheres. Meta-analysis Meta-analysis
29785-669: The slightest sense of guilt or regret. — Robert D. Hare , 1993, p. xi Personality Personality is any person 's collection of interrelated behavioral , cognitive , and emotional patterns that comprise a person’s unique adjustment to life. These interrelated patterns are relatively stable, but can change over long time periods. Although there is no consensus definition of personality, most theories focus on motivation and psychological interactions with one's environment. Trait-based personality theories, such as those defined by Raymond Cattell , define personality as traits that predict an individual's behavior. On
29970-467: The soul except for being a term to describe the cohesion of inner lives. However, some research suggests Hume excluded personal identity from his opus An Inquiry Concerning Human Understanding because he thought his argument was sufficient but not compelling. Descartes himself distinguished active and passive faculties of mind, each contributing to thinking and consciousness in different ways. The passive faculty, Descartes argued, simply receives, whereas
30155-420: The statistical validity of meta-analysis results. For test accuracy and prediction, particularly when there are multivariate effects, other approaches which seek to estimate the prediction error have also been proposed. A meta-analysis of several small studies does not always predict the results of a single large study. Some have argued that a weakness of the method is that sources of bias are not controlled by
30340-687: The striatum and reduced auto receptor availability in the midbrain. Reward dependence has been linked with the oxytocin system, with increased concentration of plasma oxytocin being observed, as well as increased volume in oxytocin-related regions of the hypothalamus . Persistence has been associated with increased striatal- mPFC connectivity, increased activation of ventral striatal-orbitofrontal-anterior cingulate circuits, as well as increased salivary amylase levels indicative of increased noradrenergic tone. It has been shown that personality traits are more malleable by environmental influences than researchers originally believed. Personality differences predict
30525-593: The study of disease since 1610, and psychopathology has meant the study of mental disorder in general since 1847. A sense of "a subject of pathology, morbid, excessive" is attested from 1845, including the phrase pathological liar from 1891 in the medical literature). The term psychopathy initially had a very general meaning referring to all sorts of mental disorders and social aberrations, popularised from 1891 in Germany by Koch's concept of "psychopathic inferiority" ( psychopathische Minderwertigkeiten ). Some medical dictionaries still define psychopathy in both
30710-520: The subjective choices more explicit. Another potential pitfall is the reliance on the available body of published studies, which may create exaggerated outcomes due to publication bias , as studies which show negative results or insignificant results are less likely to be published. For example, pharmaceutical companies have been known to hide negative studies and researchers may have overlooked unpublished studies such as dissertation studies or conference abstracts that did not reach publication. This
30895-409: The temperament of philosophers influenced their philosophy. Temperament thus conceived is tantamount to a bias. Such bias, James explained, was a consequence of the trust philosophers place in their own temperament. James thought the significance of his observation lay on the premise that in philosophy an objective measure of success is whether philosophy is peculiar to its philosopher or not, and whether
31080-456: The temperaments reflect dimensions rather than distance categories. The harm avoidance trait has been associated with increased reactivity in insular and amygdala salience networks, as well as reduced 5-HT2 receptor binding peripherally, and reduced GABA concentrations. Novelty seeking has been associated with reduced activity in insular salience networks increased striatal connectivity. Novelty seeking correlates with dopamine synthesis capacity in
31265-510: The term psychopath to designate any criminal whose offenses are particularly abhorrent and unnatural, but that is not its original or general psychiatric meaning. The word element socio - has been commonly used in compound words since around 1880. The term sociopathy may have been first introduced in 1909 in Germany by biological psychiatrist Karl Birnbaum and in 1930 in the US by educational psychologist George E. Partridge , as an alternative to
31450-556: The three outcomes. Individual studies give similar results for adult offenders, forensic psychiatric samples, community samples, and youth. The PCL-R is poorer at predicting sexual re-offending. This small to moderate effect appears to be due largely to the scale items that assess impulsive behaviors and past criminal history, which are well-established but very general risk factors. The aspects of core personality often held to be distinctively psychopathic generally show little or no predictive link to crime by themselves. For example, Factor 1 of
31635-402: The tip of the funnel. If many negative studies were not published, the remaining positive studies give rise to a funnel plot in which the base is skewed to one side (asymmetry of the funnel plot). In contrast, when there is no publication bias, the effect of the smaller studies has no reason to be skewed to one side and so a symmetric funnel plot results. This also means that if no publication bias
31820-648: The top 5% highest psychopathy scores at age 13, less than one third (29%) were classified as psychopathic at age 24. Some recent studies have also found poorer ability at predicting long-term, adult offending. Conduct disorder is diagnosed based on a prolonged pattern of antisocial behavior in childhood and/or adolescence, and may be seen as a precursor to ASPD. Some researchers have speculated that there are two subtypes of conduct disorder which mark dual developmental pathways to adult psychopathy. The DSM allows differentiating between childhood onset before age 10 and adolescent onset at age 10 and later. Childhood onset
32005-489: The two terms may be used with different meanings that reflect the user's views on its origins and determinants. Hare contended that the term sociopathy is preferred by those who see the causes as due to social factors and early environment, and the term psychopathy is preferred by those who believe that there are psychological, biological, and genetic factors involved in addition to environmental factors. Hare also provides his own definitions: he describes psychopathy as lacking
32190-725: The two-factor model of the PCL-R, studies which separate Factor 1 into interpersonal and affective facets, more regularly show modest associations between Facet 1 and low anxiety, boldness and fearless dominance (especially items assessing glibness/charm and grandiosity). When both psychopathy and low anxiety/boldness are measured using interviews, both interpersonal and affective facets are both associated with fearlessness and lack of internalizing disorders. The importance of low anxiety/fearlessness to psychopathy has historically been underscored through behavioral and physiological studies showing diminished responses to threatening stimuli (interpersonal and affective facets both contributing). However, it
32375-497: The type of intelligence assessment (e.g. verbal, creative, practical, analytical). A large body of research suggests that psychopathy is associated with atypical responses to distress cues from other people, more precisely an impaired emotional empathy in the recognition of, and response to, facial expressions , body gestures and vocal tones of fear , sadness , pain and happiness . This impaired recognition and reduced autonomic responsiveness might be partly accounted for by
32560-423: The use of meta-analysis has only grown since its modern introduction. By 1991 there were 334 published meta-analyses; this number grew to 9,135 by 2014. The field of meta-analysis expanded greatly since the 1970s and touches multiple disciplines including psychology, medicine, and ecology. Further the more recent creation of evidence synthesis communities has increased the cross pollination of ideas, methods, and
32745-464: The way effects can vary from trial to trial. Newer models of meta-analysis such as those discussed above would certainly help alleviate this situation and have been implemented in the next framework. An approach that has been tried since the late 1990s is the implementation of the multiple three-treatment closed-loop analysis. This has not been popular because the process rapidly becomes overwhelming as network complexity increases. Development in this area
32930-412: The will with the understanding and explains the common distinction of these things as being two different things as an error which results from the individual's misunderstanding of the nature of thinking. The biological basis of personality is the theory that anatomical structures located in the brain contribute to personality traits. This stems from neuropsychology , which studies how the structure of
33115-586: The world, suggesting that these underlying factors are common across cultures. There are some differences across culture, but they may be a consequence of using a lexical approach to study personality structures, as language has limitations in translation and different cultures have unique words to describe emotion or situations. Differences across cultures could be due to real cultural differences, but they could also be consequences of poor translations, biased sampling, or differences in response styles across cultures. Examining personality questionnaires developed within
33300-778: Was American psychiatrist Hervey Cleckley . In his classic monograph, The Mask of Sanity (1941), Cleckley drew on a small series of vivid case studies of psychiatric patients at a Veterans Administration hospital in Georgia to provide a description for psychopathy. Cleckley used the metaphor of the "mask" to refer to the tendency of psychopaths to appear confident, personable, and well-adjusted compared to most psychiatric patients, while revealing underlying pathology through their actions over time. Cleckley formulated sixteen criteria for psychopathy. The Scottish psychiatrist David Henderson had also been influential in Europe from 1939 in narrowing
33485-497: Was not always egocentric, callously disregarding of feelings or lacking impulse control, and there is no proof he could not learn from mistakes. Psychopaths are social predators who charm, manipulate, and ruthlessly plow their way through life, leaving a broad trail of broken hearts, shattered expectations, and empty wallets. Completely lacking in conscience and in feelings for others, they selfishly take what they want and do as they please, violating social norms and expectations without
33670-526: Was published in 1978 on the effectiveness of psychotherapy outcomes by Mary Lee Smith and Gene Glass . After publication of their article there was pushback on the usefulness and validity of meta-analysis as a tool for evidence synthesis. The first example of this was by Han Eysenck who in a 1978 article in response to the work done by Mary Lee Smith and Gene Glass called meta-analysis an "exercise in mega-silliness". Later Eysenck would refer to meta-analysis as "statistical alchemy". Despite these criticisms
33855-632: Was related to more violent and non-violent offences but not more sexual offences. For child molesters , psychopathy was associated with more offences. A study on the relationship between psychopathy scores and types of aggression in a sample of sexual murderers, in which 84.2% of the sample had PCL-R scores above 20 and 47.4% above 30, found that 82.4% of those with scores above 30 had engaged in sadistic violence (defined as enjoyment indicated by self-report or evidence) compared to 52.6% of those with scores below 30, and total PCL-R and Factor 1 scores correlated significantly with sadistic violence. Despite this, it
34040-526: Was revised in 1991 (PCL-R), and is the most widely used measure of psychopathy. There are also several self-report tests, with the Psychopathic Personality Inventory (PPI) used more often among these in contemporary adult research. Famous individuals have sometimes been diagnosed, albeit at a distance, as psychopaths. As one example out of many possible from history, in a 1972 version of a secret report originally prepared for
34225-403: Was then abandoned in favor of the Bayesian and multivariate frequentist methods which emerged as alternatives. Very recently, automation of the three-treatment closed loop method has been developed for complex networks by some researchers as a way to make this methodology available to the mainstream research community. This proposal does restrict each trial to two interventions, but also introduces
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