Encyclopedia of Psychology and Law

further refinement of existing theories will lead to

future discoveries in the psychology of homicide.

Jennifer Pryor and

Richard L. Michalski

See also Antisocial Personality Disorder; Child

Maltreatment; Criminal Behavior, Theories of; Intimate

Partner Violence; Media Violence and Behavior;

Minnesota Multiphasic Personality Inventory–2

(MMPI–2); Mood Disorders; Psychotic Disorders

Further Readings

Bancroft, C. P. (1898). Subconscious homicide and suicide;

their physiological psychology. American Journal of

Insanity, 55,263–273.

Buss, D. M., & Duntley, J. D. (2006). The evolution of

aggression. In M. Schaller, J. A. Simpson, & D. T.

Kenrick (Eds.),Evolution and social psychology

(pp. 263–285). New York: Psychology Press.

Daly, M., & Wilson, M. (1988). Homicide.New York: Aldine

de Gruyter.

Daly, M., & Wilson, M. (1997). Crime and conflict:

Homicide in evolutionary psychology perspective. Crime

& Justice, 22,51–100.

Nisbett, R. E. (1993). Violence and U.S. regional culture.

American Psychologist, 48,441–449.

Smith, M. D., & Zahn, M. (2004). Homicide: A sourcebook

of social research.Thousand Oaks, CA: Sage.

HOPKINSCOMPETENCY

ASSESSMENTTEST(HCAT)

The Hopkins Competency Assessment Test (HCAT)

was developed as a brief screening measure for

assessing a patient’s capacity to provide informed

consent and prepare advance directives regarding

medical treatments. As mental health clinicians have

increasingly recognized the importance of accurately

assessing a patient’s ability to provide informed con-

sent, the need for measures to quantify this ability has

grown. The HCAT represents one of the first such

efforts at developing a standardized approach to eval-

uating the capacity to provide informed consent by

providing a systematic measure of comprehension.

Although primarily used in research settings, this

measure has the potential to help inform clinical judg-

ments about decision-making competence.

The HCAT, developed by Jeffrey Janofsky, consists

of a short description of the informed consent process

and the durable power of attorney, followed by six

questions (e.g., What are four things a doctor must tell

a patient before beginning a procedure?). These ques-

tions evaluate the patient’s comprehension of the infor-

mation disclosed and yield a score ranging from 0 to

10, with scores of 3 or lower signifying inadequate

comprehension. In their validation study, Janofsky and

colleagues provided interrater reliability for the HCAT

by analyzing the ratings of two independent examiners

on a series of 16 cases. Not surprisingly, given the sim-

plicity of the scoring system, the authors found a corre-

lation of .95, suggesting a high degree of consistency in

HCAT scoring. Other forms of reliability, however,

have not been analyzed and are potentially less salient.

For example, because the clinical condition of many

patients changes over time, test-retest reliability is not

necessarily a meaningful index of scale reliability.

The content validity of the HCAT has been evalu-

ated in several research studies. For example, Jeffrey S.

Janofsky and colleagues compared the results of the

HCAT with the opinion of an experienced psychiatrist

who was not shown the HCAT results. All individuals

whom the psychiatrist considered incompetent had

received a score of 3 or less on the HCAT, whereas

none of the individuals who “failed” the HCAT were

considered competent by the psychologist (i.e., a 100%

accuracy rate for determination of competence).

Barton, on the other hand, found very little concor-

dance between HCAT scores and clinician opinions

regarding competence; however, the latter were based

on hospital records indicating that a patient had been

considered incompetent (which rarely occurred).

Subsequent studies have analyzed the association

between HCAT scores and ratings of patient functional

impairment, as well as performance on other measures

of cognitive functioning. For example, Sorger et al.

(2007) found markedly poorer decision-making abil-

ity, based on the HCAT, among elderly patients diag-

nosed with terminal cancer compared with a

physically healthy elderly sample, even after control-

ling for other group differences (e.g., age, gender, etc).

Nearly half (44%) of the terminally ill patients studied

“failed” the HCAT compared with only 6% of

an ambulatory nursing home comparison sample.

Moreover, HCAT scores were significantly correlated

with other measures of cognitive functioning including

the Mini-Mental State Exam.

Despite strong preliminary data in support of the reli-

ability and validity of the HCAT, this measure is rarely

Hopkins Competency Assessment Test (HCAT)——— 359

H-Cutler (Encyc)-45463.qxd 11/18/2007 12:43 PM Page 359