Encyclopedia of Psychology and Law

internal consistency of the PPI–R Total score in an

offender sample is somewhat lower (.84), with the

internal consistencies of the PPI–R content scales

ranging from .71 to .83.

Validity

Numerous studies in college and offender samples pro-

vide support for the construct validity of the PPI and

PPI–R. The Total scores on these measures correlate

moderately to highly with other self-report, interview-

based, and observer measures of psychopathy. The PPI

Total score correlates moderately with measures of per-

sonality disorders known to overlap with psychopathy,

such as narcissistic, histrionic, and borderline personal-

ity disorders, but weakly with measures of most other

(e.g., schizoid) personality disorders. Moreover, the

PPI and PPI–R Total scores display adequate discrimi-

nant validity from measures of constructs that are theo-

retically distinct from psychopathy (e.g., depression,

schizotypy, psychosis proneness, social desirability).

In addition, the PPI and PPI–R Total scores corre-

late negatively with several traits of the well-known

“five-factor model” of personality, especially Consci-

entiousness and Agreeableness, and positively with

measures of sensation seeking and Machiavellianism.

Finally, the PPI Total score demonstrates positive cor-

relations with measures of delinquent behaviors and

substance abuse, laboratory measures of poor impulse

control and planning, and offender disciplinary infrac-

tions. Future research should help determine whether

(a) the PPI–R exhibits incremental validity above and

beyond other well-validated measures of psychopathy

(e.g., the largely interview-based Psychopathy

Checklist–Revised), (b) observer reports of psychopa-

thy can supplement the PPI–R by filling in some of

the “blind spots” generated by psychopathic individu-

als’ lack of insight regarding the nature of their symp-

toms, and (c) the PPI–R can help identify potentially

adaptive expressions of psychopathy, such as charis-

matic leadership and heroic forms of altruism.

Scott O. Lilienfeld and Michelle R. Widows

See alsoForensic Assessment; Psychopathy Checklist–

Revised

Further Readings

Cleckley, H. (1988). The mask of sanity: An attempt to clarify

some issues about the so-called psychopathic personality

(5th ed.). Augusta, GA: Emily S. Cleckley.

Lilienfeld, S. O., & Andrews, B. P. (1996). Development

and preliminary validation of a self-report measure

of psychopathic personality traits in noncriminal

populations. Journal of Personality Assessment,

66,488–524.

Lilienfeld, S. O., & Widows, M. R. (2005). Psychopathic

Personality Inventory–Revised (PPI–R) professional

manual. Lutz, FL: Psychological Assessment Resources.

PSYCHOPATHY

Although psychopathy may be viewed as an evolu-

tionary adaptation that serves the individual well, it

typically is construed as a personality disorder, or a

chronic, inflexible, and maladaptive pattern of relating

to the world. Most conceptualizations of psychopathy

emphasize traits of emotional detachment, including

callousness, failure to form close emotional bonds,

low anxiety proneness, remorselessness, and deceit-

fulness. However, the most widely used measure

of psychopathy goes beyond these traits to assess

repeated involvement in antisocial behavior. The

Revised Psychopathy Checklist (PCL–R) was devel-

oped with criminal offenders and weighs past antiso-

cial behavior as strongly as traits of emotional

detachment in diagnosing psychopathy. Predominant

use of the PCL–R and offender samples has estab-

lished a large research literature on unsuccessful psy-

chopathy. Relatively little is known about individuals

with traits of emotional detachment who escape con-

tact with the legal system; express their psychopathic

tendencies in a manner that does not conflict with the

law; or even attain success in business, political, and

other settings. Indeed, most contemporary research

and virtually all practical interest in psychopathy

revolve around the utility of the PCL–R in forecasting

offenders’ violent and antisocial behavior and, to a

lesser extent, offenders’ treatment amenability. Recent

research challenges the prevailing assumptions that

(a) traits of emotional detachment per se predict vio-

lence and (b) individuals with psychopathic traits can-

not be effectively treated. In this entry, research on

these practical issues is reviewed before turning to

more fundamental questions about the basic nature and

manifestations of psychopathy. Theoretically driven

research on the potential mechanisms that underpin the

disorder reveal the importance of emotional detach-

ment as a likely manifestation of classic or “primary”

psychopathy. Such research also suggests that there

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