The share who satisfy the criteria is much higher among prison inmates. Nearly 20 percent of all inmates in Norwegian prisons are psychopaths. He recognises the impression that the media might be giving that psychopaths are lurking behind every corner. He clarified this in an interview with the psychology journal Katarsis, which is published by students at the University of Bergen. In the interview he relates to coming across literature which claims that five percent of the population is comprised of psychopaths.
He thinks the concept of Psychopathy gets misused. Various personality disorders are lumped together and called psychopathy. Psychopathy is not a psychiatric diagnosis. According to SIFER, personality disorders are deviant, dysfunctional and impractical ways of thinking, feeling and interacting with others. The most serious so-called antisocial personality disorders refer to psychopathy. And finally, while most of us respond to higher-level needs, such as family , religion or spirituality, and self-esteem, psychopaths remain occupied with those needs associated with a more basic existence.
Their analysis revealed that psychopaths used about twice as many words related to basic physiological needs and self-preservation, including eating, drinking and monetary resources than the nonpsychopaths, they write. By comparison, the nonpsychopathic murderers talked more about spirituality and religion and family, reflecting what nonpsychopathic people would think about when they just committed a murder, Hancock said.
The researchers are interested in analyzing what people write on Facebook or in other social media, since our unconscious mind also holds sway over what we write. By analyzing stories written by students from Cornell and the University of British Columbia, and looking at how the text people generate using social media relates to scores on the Self-Report Psychopathy scale.
Unlike the checklist, which is based on an extensive review of the case file and an interview, the self report is completed by the person in question. This sort of tool could be very useful for law enforcement investigations, such as in the case of the Long Island serial killer , who is being sought for the murders of at least four prostitutes and possibly others, since this killer used the online classified site Craigslist to contact victims, according to Hancock.
Text analysis software could be used to conduct a "first pass," focusing the work for human investigators, he said. Knowing a suspect is a psychopath can affect how law enforcement conducts investigations and interrogations, Hancock said.
United Kingdom-Australia vs. The significance of the differences in the joint prevalences of the different subgroups was tested with individual meta-regression analyses for each of these moderator variables and through a multiple meta-regression analysis with all the moderator variables that were statistically significant in individual analyses. In the case of the two moderator variables with three categories sample type and country , two binary dummy variables were created for each of them for the meta-regression analyses.
A total of 16 unique samples of participants from 15 studies were used to estimate the prevalence of psychopathy in the general adult population because, in one of the studies listed in Table 1 Boduszek et al. The 16 samples included a total of 11, people who were mostly university students, with seven samples The samples of participants came mainly from the USA, with five samples To study the influence of the country of origin on the prevalence of psychopathy, the samples were grouped into three categories: North America USA and Canada: In the remaining study it was done through an interview 6.
Figure 2 presents the prevalence rates of psychopathy found in the 16 samples of the general population analyzed in the present work, and also the joint prevalence rate. Figure 2. Forest plot of the prevalence in proportions of psychopathy in the general population. Moreover, both the Doi chart and the LFK index suggested that this heterogeneity did not seem to translate into a large asymmetry that could reflect a significant publication bias, because, for example, the LFK index obtained 0.
Figure 3. Indicators to evaluate the skewness of the results of the studies and detect the presence of publication biases: Doi chart and LFK index obtained in studies on the prevalence of psychopathy in the general population. As can be seen in Figure 4 , studies using instruments other than the PCL-R found much higher rates of psychopathy prevalence more than triple or quadruple, on average than studies that used the PCL-R or any of its versions, with the combined prevalence of 5.
Figure 4. Forest plot of the prevalence in proportions of psychopathy in the general population depending on the type of instrument used to measure psychopathy: PCL-R vs. For its part, the combined prevalence of psychopathy in samples of organizations [ In fact, in the individual meta-regression analysis, the two binary dummy variables created were statistically significant: organizations vs.
Figure 5. Forest plot of the prevalence in proportions of psychopathy in the general population depending on the type of sample evaluated: organizations, community, or university students. As only 5 of the 15 studies listed in Table 1 offered separate prevalence rates for male and female subsamples Hagnell et al.
In particular, the combined prevalence of psychopathy was higher more than double in males [7. Figure 6. Forest plot of the prevalence in proportions of psychopathy in the general population based on gender. The main objective of this study was to obtain an estimate of the prevalence of psychopathy in the general adult population and, in this sense, to our knowledge, it is the first systematic or meta-analytic review carried out on this topic.
Following a thorough search in the scientific literature, 15 empirical studies were found that had calculated the frequency of psychopathy in samples from the general adult population, including community, organization, and university student samples. These studies used properly described tools and procedures to assess and define psychopathy. After calculating the conjoint mean of their results with meta-analytic procedures, based on a total sample of 11, people, it can be estimated that the prevalence of psychopathy in the general adult population is 4.
As could be expected, this prevalence is much lower than that found in samples obtained in forensic or prison contexts. For example, in the meta-analysis of Fox and DeLisi , it was found that the average prevalence of psychopathy among homicide offenders could be estimated at In the second edition of the PCL-R manual Hare, a , the prevalence of psychopathy, based on a cut-off score of 30, was In fact, the results obtained in terms of the I 2 and Q statistics confirmed that the heterogeneity of the studies was statistically significant.
These variations depend on many factors, such as the role of the type of instrument used to define psychopathy, the participants' sex, the type of sample of the general population, and the participants' country of origin. These factors have been analyzed in this work.
In this sense, the results of the present work indicate that the first three factors, but not the country of origin, seem to have a significant impact on the prevalence of psychopathy. Depending on the chosen instrument, the participants' sex or the type of sample selected, prevalence figures can double, triple, or quadruple the figures found with a different instrument or with participants of another sex or from a different subpopulation of the general population.
Moreover, the results obtained in terms of the Doi chart and the LFK index indicate that this heterogeneity does not appear to reflect a significant publication bias, but could largely be attributed to these three moderator variables. In particular, the results of this work indicate that, when using the PCL-R or any of its versions , an instrument that is currently considered as the gold standard for the evaluation and definition of psychopathy, it can be estimated that the prevalence of psychopathy in the general adult population is only 1.
However, if other instruments are used, such as self-reports of psychopathic personality traits like the LSRP Levenson et al. In fact, as virtually all the studies with offenders use the PCL-R or one of its versions, the comparison between the prevalence rates of psychopathy obtained in the general population and in the offender or prison population should primarily focus on studies conducted with the PCL-R. In this sense, the difference in the prevalence rate of psychopathy between the two types of population, general and criminal, is much greater: 1.
Differences in the prevalence rates as a function of the type of instrument and cut-off point established to identify psychopathy go back to the problems in defining the construct of psychopathy.
Those differences also point out a limitation of the present study. We will elaborate on these ideas later in the context of the limitations of this review. The results of this study also indicate that the prevalence of psychopathy in the general adult population is significantly higher among males than among females.
In particular, psychopathy in the general population doubles its prevalence in males compared to females 7. This difference is consistent with the results obtained in samples of offenders or incarcerated people, among whom the prevalence of psychopathy is also higher in males than in females Beryl et al. In particular, Beryl et al. However, from the data they submitted for females in criminal justice settings, it is possible to calculate, for the 13 unique studies that defined psychopathy based on a cut-off score of 30 in the PCL-R or of 18 in the PCL:SV, a weighted average prevalence of Moreover, these figures hardly varied when only studies using the same instrument, the PCL-R, and the same cut-off score, 30 Interestingly, these prevalence figures are very similar to those presented by the scales of female prisoners collected in the second edition of the PCL-R manual, which, as noted above, show a prevalence of psychopathy in female prisoners of However, in the second edition of the PCL-R manual, published in and based on a much larger sample with a total of 5, males incarcerated in American prisons, Hare reported that Finally, in the meta-analysis of Fox and DeLisi , it was found that Another interesting result of this work has to do with the finding of differences in the prevalence of psychopathy between different groups of adults in the general population.
In particular, this review has found that the prevalence of psychopathy is significantly higher among workers in some organizations and companies managers, executives, procurement and supply professionals, advertising workers than among university students or among people from the general community In turn, the prevalence among university students is significantly higher than among people from the general community 8.
The highest prevalence of psychopathy among workers in certain organizations and companies is based on data from only three studies with a total sample of people and should, therefore, be taken with some caution. However, this result is consistent with the scientific literature that proposes that psychopathy is more prevalent in certain professions e.
More surprising may be the result that among university students, there is a higher prevalence of psychopathy than among people in the community. Following the previous argument, it could be assumed that among university students of certain professions there could be more people with psychopathic traits e.
In fact, in a study of Hassall et al. Unfortunately, this work did not provide data on the prevalence of psychopathy in the two groups of university students.
In addition, in the study of Dutton , mentioned in the Introduction, among the 10 professions with higher levels of psychopathic traits, there were some that require a university degree e.
Therefore, future research with university students should examine whether there are significant differences in psychopathy among students of different careers. This implies that, not only among university students of certain careers may there be a higher prevalence of psychopathy than in the general population, but that among university students of other careers, there may be a similar prevalence.
It could even be that among university students of certain careers, there may be a lower prevalence of psychopathy than in the general population. Research on differences in psychopathy between people of different professions or between university students of different careers departs from the traditional application of the construct of psychopathy to the forensic and prison area.
That research intertwines, as discussed in the Introduction, with the most recent interest in the presence of psychopathy in everyday life Dutton, ; Babiak and Hare, ; Fritzon et al. The fact that, as found in this review, most studies on the prevalence of psychopathy in the general population were published in the twenty-first century, especially in the last 10 years, is also consistent with those most recent interests far from the area of forensic and prison psychology.
Finally, no significant differences in the prevalence of psychopathy in the general population were found in this work as a function of the country of origin of the evaluated people. This absence of differences is not consistent with the results of the scientific literature on criminal and prison populations, which show the existence of differences between countries, especially between North American and European countries, in terms of the prevalence and levels of psychopathy in this type of population.
For example, in the review of Beryl et al. Consistently, in the meta-analysis of Fox and DeLisi , and after discarding the extreme values from samples composed exclusively of homicides with psychosis or psychopathy, significantly higher levels of PCL-measured psychopathy were found in homicide offenders from the USA and Canada than in homicide offenders from Finland, Sweden, and Germany.
Although these two reviews have reported that psychopathy prevalence is higher in North American male and female offenders and prisoners than in European male and female offenders and prisoners, the reasons for these differences are unclear. Beryl et al. However, following the cultural facilitation model and Cooke et al. Therefore, it may be that socialization and enculturation in European countries suppress the development of certain psychopathic personality traits, or that those social processes in North American countries facilitate the development of certain psychopathic personality traits.
There is also the possibility that both explanations are valid. In any case, the results of the present review suggest that those differences between countries in the prevalence of psychopathy are unique to the prison or criminal population, but do not extend to the general population.
However, studies using samples from the general population of many different countries around the world have found cultural differences in the levels of different psychopathic traits. For example, in the study of Neumann et al. To further complicate the scenario of empirical results on the relationships between psychopathy and culture, the differences found in some studies with samples from the general population sometimes go in the opposite direction to those found in offender or prisoner populations.
Thus, in the study of Lilienfeld et al. As a result, future research should address whether differences between countries in psychopathy only appear in terms of levels of certain psychopathic traits, but not in terms of the prevalence of psychopathy.
It should also be examined whether such differences translate into a pattern of consistent differences between North American and European countries. The results obtained in this work and the conclusions that have been reached should be assessed taking into account some of the limitations of the review itself.
The most important limitations concern the high variability of the characteristics of the reviewed studies and the prevalence rates found, the small number of studies conducted to date that can help control such variability, and the methods assessing psychopathy in the reviewed studies. As already mentioned, prevalence rates vary greatly depending on factors such as the type of instrument used to define psychopathy, the participants' sex, and the type of sample from the general population.
Given the small number of studies that currently constitute the scientific literature on the prevalence of psychopathy in the general population and the great heterogeneity of these studies in terms of their characteristics, it is very difficult to examine the effects of one of its factors while controlling the effect of the remaining factors. Therefore, in that smaller set, factors such as the type of instrument or sample did not reach statistical significance, thus preventing a more statistically potent analysis of the effect of gender after controlling the effects of these two factors and vice versa.
Among the factors that affected the variability of the prevalence of psychopathy, it is worth highlighting the type of instrument used to define psychopathy, since this factor points out important issue underlying this review.
There is a high heterogeneity in the methods used to assess psychopathy in the reviewed studies. In addition, some of these method are more susceptible to criticisms related to their reliability and validity than others e. That heterogeneity and these criticisms go back to the problems in defining the construct of psychopathy. The different theoretical perspectives for this purpose which characterize the research of this construct are also an issue, and have already been discussed in the Introduction.
In this sense, for example, an interesting exchange of views has recently been published on the debate over what components are essential to, or constitute part of psychopathy. Consequently, one of the most important challenges that research in the area of psychopathy has to face is to achieve a valid and consensual definition of the construct of psychopathy and, related to this, to decide which instrument or instruments are the most valid and reliable to measure this construct.
These needs are most evident when studying psychopathy in the general population because, as mentioned above, virtually all studies on psychopathy in the population of offenders or prisoners use the PCL-R or one of its versions see the reviews of Beryl et al.
On the other hand, future research should also focus on the prevalence of the components of psychopathy, especially on the prevalence of psychopathic traits. Moreover, future research should also be conducted on the prevalence of the other personality constructs that are included under the Dark Triad label: Machiavellianism and narcissism.
Despite the above-mentioned limitations, the obtained results reflect relatively strong trends in the data that at least deserve to be the subject of future research and the formation of hypotheses to be taken into account in such research. In short, these trends allow the following conclusions to be drawn:.
In turn, the prevalence of psychopathy among university students is significantly higher than among people from the general community, although the latter result could be due to the type of career that university students are pursuing e. The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.
This article is based in part on the final degree project carried out by AS-G under the direction of CG. AS-G organized the database and wrote the first draft of the manuscript. JS performed the statistical analysis. All authors contributed to manuscript revision, read, and approved the submitted version.
0コメント