The study examined the stability of psychopathy from age 13 to age 24 in the middle sample of the PYS. At age 13, psychopathy was assessed using mother-reports on Lynam’s (1997)
Childhood Psychopathy Scale. In early adulthood, after an average interval of 11 years, psychopathy was assessed by interviewers using the Psychopathy Checklist: Screening Version (Hart et al., 1995
). Zero-order correlations revealed moderate stability between the total score on the CPS at age 13 and the total score on the PCL:SV at age 24. The stability was the same across levels of initial risk status and initial psychopathy level. Additionally, scores on the CPS predicted each component of the PCL:SV—facet 1 which assesses an arrogant, deceitful interpersonal style, facet 2 which assesses deficient affective experience, facet 3 which assesses an impulsive and irresponsible behavioral style, and facet 4 which assesses antisocial behavior. It should be noted, however, that scores on the CPS at age 13 were most strongly related to Facets 3 and 4. Importantly, these relations survived controls for 13 different constructs: race, family structure, family SES, neighborhood SES, four measures of parenting, peer delinquency, previous delinquency, and three other individual differences.
In addition to examining relative stability across time, we examined how well psychopathy at age 13 could predict a possible diagnosis of psychopathy at age 24. In terms of diagnostic accuracy across these time points, specificity and negative predictive power were both quite good. Sensitivity was adequate at lower cut-scores, but positive predictive power was generally poor. These results may be expected given the moderate relation between scores across time and the relatively low base rate of psychopathy.
How one interprets the magnitude of the relation between adolescent psychopathy and adult psychopathy will depend on the use to which one wishes to put the construct. On the one hand, a psychopathologist, interested in identifying a potential developmental precursor to a destructive adult syndrome, will likely be encouraged by the present results. Although moderate in absolute terms, the correlation is fairly large when put into context. The lag between assessments is long, over eleven years on average, and the developmental age range spanned is marked by lower levels of trait stability. There is no overlap in the form of assessment (i.e., mother-report vs. interviewer rating), information source (i.e., mother vs. interviewer), or in the behavioral data used to make ratings. Although each assessment is based on the PCL-R, the actual constructs assessed overlap only partially.
Moreover, the correlation between the CPS at age 13 and the PCL:SV at age 24 is similar to what is typically observed when different psychopathy assessments are administered concurrently. Six recent studies (Kosson, Cyterski, Steuerwald, Neumann, & Walker, 2002
; Lee, Vincent, Hart, & Corrado, 2003
; Murrie & Cornell, 2002
; Salekin et al., 2004
; Vitacco, Rogers, & Neumann, 2003
) have used either the PCL:YV or PCL:SV along with another psychopathy assessment in juveniles (average age = 15.4). Across studies, the concurrent, cross-source correlations ranged from .35 to .62 with an average of .41. Several additional studies have examined the concurrent relation between the PCL-R and other assessments in samples of adults (Brinkley et al., Kosson, Steuerwald, Forth, & Kirkhart, 1997
; Poythress, Edens, & Lilienfield, 1998
). The concurrent cross-method correlations in these studies ranged from .35 to .54. Taking these concurrent cross-method assessments as upper-bounds for the present research, the correlation of .31 is fairly high.
Finally, psychopathologists can note that this level of relative stability is similar to the levels of relative stability observed for basic dimensions of personality. In their meta-analysis on the rank-order consistency of personality, Roberts and Del Vecchio (2000)
found the rank-order consistency of personality to be 0.43 across 6.7 years among adolescents (aged 12 to 17.9). Given that stability declines with increasing assessment intervals and divergent assessment methods, the 0.31 rank-order consistency identified in the present study is fairly consistent.
On the other hand, a forensic psychologist, concerned about decision making in a legal context, will be less impressed by the present results. Despite attempts at contextualization, the correlation remains moderate and indicates that psychopathy at age 13 accounts for 10% of the variance in age-24 psychopathy. Forensic psychologists will also be more concerned with the analyses of diagnostic stability. Although specificity and negative predictive power are good and sensitivity is adequate at some cut-points, positive predictive power is poor at all cut-points indicating that most individuals identified as “psychopaths” at age 13 will not receive such a diagnosis at age 24. The positive likelihood ratio is small, ranging between 2 and 3.5. Finally, the present assessment context, with its promise of confidentiality, the existing relationship between participants and study investigators, and the sole reliance on mother-reports at age 13 differs, markedly from the context of a forensic mental health examination (Heilbrun, 2001
Total scores on the CPS at age 13 were more strongly related to PCL:SV facets 3 and 4 than to facets 1 and 2 at age 24. Similarly, facets 1 and 2 were less well-predicted than facets 3 and 4 in the multiple regressions. The 14 predictors from age 13 accounted for 24 to 27% of the variation in facets 3 and 4, but only 14 to 16% of the variation in facets 1 and 2. There are several possible explanations. First, the CPS and the PCL:SV differ somewhat in their content. Three of the 8 PCL-R items that comprise facets 1 and 2 are not shared across the CPS and PCL:SV; whereas two items from facets 3 and 4 are not shared. Second, elements of facets 1 and 2 may be less stable across time. Certain traits, like grandiosity, glibness, and lack of guilt, may appear later developmentally in response to the behavioral consequences (e.g., alienation of parents, peers, and teachers; arrest) of other earlier appearing traits such as callousness, impulsiveness, and behavioral dyscontrol. Relatedly, the traits assessed by facets 1 and 2, which are more interpersonal in nature and depend more heavily for their assessment on interview behavior, may be more temporally limited. It is worth nothing that the present results are consistent with those reported by Skeem and Mulvey (2001)
from the MacArthur Risk Assessment Study which also employed the PCL:SV; 11 of the 15 correlations between the PCL:SV factors and validation measures in that study were stronger for Factor 2, which combines facets 3 and 4, than for Factor 1, which combines facets 1 and 2.
As with the stability for the total score, these results are subject to multiple interpretations depending upon one’s definition of psychopathy. There is an ongoing debate in the literature regarding how best to define and conceptualize the construct, particularly in regards to the role of antisocial behavior. On one end of the debate, Hare and others (e.g., Hare, 2003
; Neumann, Vitacco, Hare, & Wupperman, 2005
) have argued that antisocial behavior is a key feature of psychopathy and that psychopathy is a higher-order construct consisting of all four facets. Similarly, from a broad personality perspective, Lynam and colleagues (Lynam & Derefinko, 2006
; Lynam & Widiger, in press
) have argued that psychopathy consists of extreme scores on a diverse set of basic personality traits and that each PCL-R item, including those present in facet 4, represents an attempt to assess one or more of these traits. From these broad definitions of psychopathy, the moderate relation between age 13 psychopathy and the total score at age 24 is the most relevant one. On the other end of the debate, Skeem and Mulvey (2001)
have argued that the traits assessed by Factor 1 which combines facets 1 and 2 be considered primary; from this view, the weaker prediction of facets 1 and 2 is meaningful and suggests that the stability of psychopathy is weak rather than moderate. Somewhere in the middle of this debate, Cooke and Michie (2001)
argue that psychopathy consists of the traits present in facets 1, 2, and 3; they exclude items assessing more explicit antisocial behavior (i.e., facet 4) suggesting that these items be considered correlates or consequences of psychopathy rather than core features. From this view, the stability of psychopathy is weak to moderate.
The implications of the present study are relatively straightforward, particularly in relation to criticisms raised regarding the construct of child/adolescent psychopathy (Edens et al., 2001
; Seagrave & Grisso, 2002
). Several critics have raised concerns that developmentally normative traits might masquerade as psychopathy and have called for direct assessments of the continuity between child/adolescent and adult psychopathy. The present results directly address this concern and support the argument that adolescent psychopathy, as assessed by the CPS, is a developmental precursor to adult psychopathy, as assessed by the PCL:SV.
Another concern has been with the “added value” of child/adolescent psychopathy. “The field of child and adolescent psychopathology abounds with diagnostic categories and antisocial behavior subtyping schemes. There is no reason to introduce another such scheme unless it provides additional utility” (Lynam, 2002
; p. 258). Again, the present results directly address this concern and suggest that adolescent psychopathy is a unique risk factor for adult psychopathy. After controlling for 13 variables assessed at age 13, psychopathy assessed via the CPS continued to predict psychopathy in adulthood.
The critics have also expressed concern about the application of a pejorative label to adolescents given the wide-spread but possibly erroneous belief that psychopathy is untreatable. Although it is possible that the present results may be used to offset the application of a pejorative label, that is not the argument that we make. Rather, we believe that the relative resistance to treatment among adult psychopaths is exactly the reason that the study of child/adolescent psychopathy is to be embraced: The assessment and study of child/adolescent psychopathy holds the key to its treatment. Many researchers simply assume the stability of psychopathy in adulthood. Basic research in personality suggests, however, that stability needs to be explained. With emerging evidence that individual differences in psychopathy are stable across time, research is now needed that explores the reactive, evocative, and proactive person-environment transactions that promote stable individual differences (Caspi, 1998).
Reactive transactions occur when individuals exposed to the same environment experience, interpret, and react to it according to their pre-existing tendencies. Aggressive children make more hostile attributions in ambiguous situations, generate more aggressive responses, and are more likely to believe that aggressive responses will work. Evocative transactions occur when individuals evoke distinctive reactions from their social environments based on their personalities. Difficult-to-manage children tend to evoke characteristic reactions from parents, including harsh and erratic discipline, reduction of efforts at socialization, and increases in permissiveness. Finally, proactive transactions occur when individuals select or create social environments that are in line with their existing personalities. Individuals tend to choose similar others as friends and mates. In all cases, these person-environment transactions reinforce rather than repudiate the existing personality. In the case of psychopathic behavior, this reinforcement comes, in part, through an accumulation of negative consequences. From this perspective, psychopaths are resistant to treatment due to their accretion of negative consequences (e.g., alienation from family, addiction to drugs, involvement in a criminal peer group, school dropout, injuries, patchy work histories, and multiple incarcerations) that have closed the doors of more legitimate opportunity. From this perspective, treatment will be most effective earlier in the life course, before negative consequences have accumulated and when the opportunity exists to intervene in multiple areas (e.g., school, family, peers, and individually). Psychopathy is stable across time, in part, because we currently fail to recognize its presence early and adequately and fail to intervene effectively.
There are limitations to the present study. The most obvious is the high participant loss across the eleven years between assessments. Although there were no differences between those lost and those retained in risk status, SES at age 13, psychopathy at age 13, or seriousness of delinquent involvement at age 13, the groups did differ in the proportion of African Americans. There are sure to be other differences as well. Another limitation is the inclusion of only men in the PYS. Although this exclusion is understandable from a pragmatic standpoint given the focus of the PYS (i.e., the causes and correlates of serious delinquency) and does not influence our estimate of the stability of psychopathy for men, this exclusion precludes comparison of psychopathy across sex—an important area receiving increased interest. Finally, as regards the issue of incremental utility, we controlled for a number of variables but obviously not all of them. Psychopathy in early adolescence uniquely predicts psychopathy in young adulthood even after controlling for race, family structure, SES, neighborhood, poor parenting, bad peers, impulsivity, intelligence, and previous delinquency, but there are other important variables left uncontrolled. For example, Moffitt’s (1993)
theory posits that risk for chronic offending is highest among individuals with early starting behavior problems and certain types of neuropsychological deficits; neither of these constructs was included in the present study.
Future directions are also clear. The most straightforward involve replication using other developmental periods, samples, and assessments. In the present study, we examined the stability from early adolescence into early adulthood in a high-risk community sample from inner-city Pittsburgh using the CPS and PCL:SV. However, there are other developmental periods that can and should be examined. It will be important to examine the stability of child/adolescent psychopathy in institutional, forensic, and rural settings. There are multiple, reliable and valid means of assessing psychopathy at both the juvenile and adult levels. To the degree that similar stabilities are obtained across differing methodologies the greater will be our confidence in child/adolescent psychopathy as a developmental precursor to adult psychopathy.
Other future directions involve studies with better temporal resolution and finer grained trait-level analyses. It is important to examine stability and change across multiple assessment periods in individual traits. Research suggests that child, adolescent and adult psychopathy can be understood as a diverse collection of personality traits (e.g., Lilienfeld & Andrews, 1995; Lynam et al., 2005
; Miller, Lynam, Widiger, & Leukefeld, 2001
; Salekin et al., 2005
). Given that personality traits may show differential levels of stability across development (McGue, Bacon, & Lykken, 1993
) future research should examine the stability of individual elements of psychopathy. These studies should ideally include multiple assessments of these traits across adolescence. Although the present study suggests relative stability of psychopathy from age 13 to age 24, it says nothing about what happens to the levels, particularly the absolute levels, of psychopathy and its constituent elements in between.
For our part, one of the most important directions is an examination of the mechanisms of stability outlined above. The present results suggest that psychopathy is relatively stable from age 13 to age 24. The important next question is why? Future research should seek to understand how psychopathic traits transact with their surroundings to promote their own stability. The specification of these transactions will suggest areas of future intervention.