the PPI has “Fearless Dominance” and “Impulsive
Antisociality” scales that appear somewhat like the
two scales of the PCL–R, the PPI is not saturated with
indices of violent and antisocial behavior. The study
yielded moderate heritability estimates for both scales
(h=.45 to .49). The extent to which these results will
generalize to the context in which psychopathy is typ-
ically studied (i.e., direct assessment of PCL–R psy-
chopathy with offenders) is unclear.
In summary, the criteria for diagnosing psychopa-
thy can identify individuals with clearly delineated
deficits, particularly if they are modified to include
low anxiety and de-emphasize antisocial behavior. At
present, it is unclear whether these deficits are largely
genetically determined. However, as shown next, the
present criteria clearly do not identify a homogeneous
group of individuals as psychopathic.HHoommooggeenneeiittyy
Although psychopathy usually is treated as a uni-
tary construct, Ben Karpman’s seminal theory posits
that there are two variants: primary psychopathy is
underpinned by an inherited affective deficit, whereas
secondary psychopathy reflects an acquired affective
disturbance. Primary psychopathy is consistent with
classic conceptualizations of psychopathy as a deficit,
whereas secondary psychopathy represents a more
psychopathological, hostile, and violent variant.
Although the etiological distinctions between them
have not been rigorously investigated, there is evi-
dence that primary and secondary variants of psy-
chopathy can be identified. Despite differences in
their methodology, three studies have identified—
among offenders with PCL–R scores in the range
deemed psychopathic—primary and secondary vari-
ants. In the first study, model-based cluster analysis
was applied to 96 inmates’ scores on a measure of
general personality to identify two groups of psy-
chopaths: one emotionally stable (primary) and the
other aggressive (secondary). Although the two
groups were difficult to distinguish in their psycho-
pathic traits, secondary psychopaths reported more
fights, greater alcohol abuse, lower socialization, and
higher trait anxiety than primary psychopaths. In the
second study, model-based cluster analysis was
applied to 124 inmates’ scores on the PCL–R and a
measure of trait anxiety to reveal two groups. Relative
to primary psychopaths, secondary psychopaths had
greater trait anxiety, fewer psychopathic traits, and
comparable levels of antisocial behavior. Acrossvalidation variables, secondary psychopaths mani-
fested more borderline personality features, poorer
interpersonal functioning (e.g., withdrawal, lack of
assertiveness), more symptoms of major mental disor-
der, and greater treatment responsivity than primary
psychopaths. A similar approach was used in the third
study of 116 juvenile offenders, which also yielded
primary and secondary variants. Secondary variants
were more likely than primary variants to endorse
early childhood abuse.
These recent findings raise fundamental questions
about the nature of psychopathy. Are secondary psy-
chopaths still “psychopaths” if the mechanisms that
underpin their traits differ from psychopathy as classi-
cally construed? The findings may also have substantial
practical implications for risk assessment and risk man-
agement. Relative to primary psychopaths, secondary
psychopaths theoretically are both more prone to vio-
lence and more amenable to treatment. The next gener-
ation of research holds promise for addressing these
key questions, ideally while distinguishing between the
practical enterprise of clinical prediction and the pur-
suit of understanding the psychopathy construct.Jennifer L. Skeem and Patrick J. KennealySee alsoAntisocial Personality Disorder; Forensic
Assessment; Hare Psychopathy Checklist–Revised
(2nd edition) (PCL–R); Juvenile Psychopathy; Personality
Disorders; Psychopathic Personality Inventory (PPI);
Psychopathy, Treatment of; Psychopathy Checklist:
Screening Version; Psychopathy Checklist: Youth Version;
Risk Assessment ApproachesFurther Readings
Cleckley, H. (1976). The mask of sanity(5th ed.). St. Louis,
MO: Mosby.
Lilienfeld, S. O. (2005). Psychopathic Personality
Inventory–Revised(PPI–R). Lutz, FL: Psychological
Assessment Resources.
Lykken, D. T. (1995). The antisocial personalities. Hillsdale,
NJ: Lawrence Erlbaum.
Patrick, C. J. (2006). Handbook of psychopathy. New York:
Guilford Press.
Skeem, J. L., & Cooke, D. J. (in press). Is criminal behavior a
central component of psychopathy? Conceptual directions
for resolving the debate. Psychological Assessment.
Skeem, J., Poythress, N., Edens, J., Lilienfeld, S., & Cale, E.
(2003). Psychopathic personality or personalities?
Exploring potential variants of psychopathy and their
implications for risk assessment. Aggression & Violent
Behavior, 8,513–546.646 ———PsychopathyP-Cutler (Encyc)-45463.qxd 11/18/2007 12:43 PM Page 646