systems and by tension in the skeletal musculature.
Transfer of arousal or excitation residues from a prior
provocation can intensify anger to a new one. The
NAS Arousal subscale items operationalize intensity,
duration, somatic tension, and irritability.NNAASS BBeehhaavviioorraall
Implicit in the cognitive labeling of anger is an
inclination to act in an antagonistic or confrontative
manner. The NAS Behavioral subscale items opera-
tionalize impulsive reaction, verbal aggression, phys-
ical confrontation, and indirect expression. The NAS
Behavioral score is the principal NAS index expected
to be associated with violence.NNAASS TToottaall
This is a summary anger disposition index, created
by adding the Cognitive, Arousal, and Behavioral sub-
scales. It does not include the NAS Anger Regulation
subscale.NNAASS AAnnggeerr RReegguullaattiioonn
A central characteristic of problematic anger is loss
of regulatory control, which of course hinges on the
environmental context in which the anger has been
activated. This subscale is composed of cognitive,
arousal, and behavior items. It is an overall index of
the person’s report of his or her ability to regulate
anger-engendering thoughts and thinking styles, effect
self-calming, and engage in constructive behavior
when faced with provocation.IInnccoonnssiisstteenntt RReessppoonnddiinngg IInnddeexx ((IINNCC))
As a validity check, the NAS contains an index of
response inconsistency, computed from a subset of
8 item pairs that have high correlations in the WPS
standardization sample. Details are given in the NAS-
PI manual.Reliability
In its initial version, the NAS Total had an internal
reliability (alpha) of .95 and a 2-week test-retest reli-
ability of .84 in studies with psychiatric patients in the
California State hospitals. An independent study withmale offenders in Canada found NAS Total alpha
equal to .95 and test-retest reliability to be .89 for a
4-week interval. In the MacArthur Violence Risk
Project involving 1,101 civil commitment psychiatric
patients, who were given the NAS while in hospital,
the alpha for NAS Total was .94. For the WPS stan-
dardization sample, it was .94. In other studies, the
NAS Total alpha was .97 for Vietnam combat veter-
ans, .95 for forensic patients in Scotland, .92 for
developmental disabled forensic patients in England,
.94 for violent prisoners in Sweden, and .90 to .93 for
undergraduates in California, Australia, and Sweden.Validity
The initial NAS-PI was validated in the MacArthur
Violence Risk Project, directed by John Monahan
and conducted in three U.S. metropolitan areas. The
NAS was a significant predictor of postdischarge
violence at 10-week and 1-year follow-ups. It was
also significantly related to patients’ imagined vio-
lence while in hospital. In the scale development
studies with California patients, it correlated .42 and
.47 with Spielberger State Anger, prospectively at
1 and 2 months, respectively. It has robust correla-
tions with the Spielberger Trait Anger measure in
concurrent testing in studies with psychiatric
patients in California, Scotland, England, Canada,
and Sweden and with Vietnam veterans in Hawaii.
Independent studies have found it to be related to
violence by psychiatric patients before hospital
admission, during hospitalization, and in the com-
munity after hospital discharge. Among combat vet-
erans, it is strongly related to PTSD symptoms and
PTSD diagnosis. Its adaptation to developmental
disabilities patients has been demonstrated to have
high reliability and validity and to be predictive of
assaultive behavior in hospital.Future Directions
The NAS-PI manual elaborates on the theoretical
background and history of instrument development,
the principles for its use and interpretation, validity
issues, and the psychometric properties ascertained
from a number of research investigations. One
intended use of the NAS is for evaluation of the treat-
ment received. An important extension in this domain
would be for case formulation. Given that anger is nowNovaco Anger Scale——— 527N-Cutler (Encyc)-45463.qxd 11/18/2007 12:43 PM Page 527