of ASPD. Therefore, almost anything that predicts
chronic crime and violence ostensibly could be con-
sidered a candidate etiological factor for ASPD.
Nevertheless, there is evidence for certain genetic,
biological, and environmental etiological mechanisms
in ASPD. Large-scale twin and adoption research
shows a high degree of heritability for PDs generally,
as well as for ASPD specifically. An interesting line of
research by Robert Krueger and colleagues has shown
that ASPD might be construed as part of a heritable
externalizing spectrum of psychopathology that
includes antisocial personality features and behavior,
substance use problems, conduct problems, sensation
seeking, and low constraint.
Potential biological mechanisms include neurochem-
ical imbalances, such as low serotonin levels, that are
related to impulsive and aggressive behavior. Some bio-
logical etiological mechanisms have been advanced
more specifically for psychopathy, which includes addi-
tional interpersonal and emotional deficits. For instance,
some experts propose that psychopathy, and as such
some cases of ASPD, is associated with functional brain
deficits, such as a diminished ability to process emotion
or impaired information processing. Other mechanisms
could include temperamental deficiencies, such as
decreased startle potentiation. Structural, as opposed to
functional, neuroanatomic models have been proposed
as well, including deficits in prefrontal and temporal
lobe gray matter. It is important to note that all such
research on the biological mechanisms of psychopathy
and ASPD is in its infancy and cannot yet support defin-
itive statements about clear etiological factors.
Environmental factors also may elevate the risk of
development of ASPD. For instance, abusive, inconsis-
tent, or permissive parental disciplinary styles predict
delinquency and adult criminality. Similarly, other
family-of-origin and formative experiences predict
delinquent and criminal behavior, such as parental crim-
inality, violence, and substance use problems. Social
learning theory would posit that such parental behaviors
model criminal behavior for children, who then learn to
use crime and violence in their own lives.
Of course, many such parental factors could be
acting as mere proxies for genetic etiological mecha-
nisms, and future research will need to disentangle
genetic from environmental risk factors. Some inter-
esting emerging research has started to do so. For
instance, parental physical maltreatment of children
has been found to predict antisocial behavior above
and beyond the heritable aspects of parental antiso-
ciality. Furthermore, research is starting to addressgene-environment interactions vis-à-vis antisocial
behavior and personality, which posit that genetic and
environmental factors might be multiplicative in their
influence on such outcomes rather than merely additive.Controversies
The ASPD diagnosis has generated controversy on sev-
eral fronts. The debate that has received the most com-
mentary pertains to whether the diagnostic criteria
should emphasize objective behaviors or personality
features. The introduction of ASPD into the DSM was
intended to reflect the clinical disorder known as psy-
chopathy, which includes features such as callousness,
remorselessness, guiltlessness, superficiality, and shal-
low affect. The ASPD criteria were written with a
behavioral focus in the service of the decreasing sub-
jectivity involved in rating personality features, thereby
increasing reliability. In the current diagnostic nomen-
clature, ASPD is presented as being largely the same as
psychopathy—even though many of the descriptors tra-
ditionally associated with psychopathy are absent from
the diagnostic criteria. That the two disorders are not in
fact synonymous is highlighted by the results of con-
temporary prevalence studies demonstrating that about
three quarters of prisoners meet the criteria for ASPD
whereas only about one quarter, or less, meets the cri-
teria for psychopathy.
Additionally, the criteria have been criticized for lack-
ing specificity; for instance, meeting diagnostic criteria
may arise from a boggling number of permutations of
the 7 adult disorder and 15 CD symptoms. An important
impact of the imprecision with which the outcome of
ASPD is delineated is that it renders investigation into
the disorder’s causal factors much more challenging, as
noted above. Moreover, the validity of ASPD has been
challenged in light of the paucity of available longitudi-
nal data. Critics of the ASPD criteria also argue that they
are underinclusive (in that individuals will not be identi-
fied who have the core antisocial personality features but
have not been criminally sanctioned or who demonstrate
antisociality during adulthood but for whom there is no
evidence of CD). In contrast, others advance concerns
that the criteria are overinclusive (in that there likely are
several etiological bases for antisociality, only one of
which may be psychopathy). As noted earlier, the crite-
ria largely reflect the behavioral difficulties associated
with crime and substance use. This is noted to be prob-
lematic because behaviors can be influenced by external
circumstances, whereas personality traits are viewed as
being more reflective of underlying pathology.32 ———Antisocial Personality DisorderA-Cutler (Encyc)-45463.qxd 11/18/2007 12:41 PM Page 32