Novaco Anger Scale

The Novaco Anger Scale (NAS) is a self-report questionnaire with Cognitive, Arousal, and Behavioral subscales that constitute a 48-item NAS Total score. It has a separate 12-item Anger Regulation subscale. This questionnaire is designed to index a person’s disposition for anger, which is a risk factor for violence and a dynamic variable amenable to treatment. The NAS was developed in conjunction with the violence risk project of the MacArthur Foundation Research Network on Mental Health and Law. It was later revised, along with its companion scale, the 25-item

Provocation Inventory (PI), in conjunction with its publication by Western Psychological Services (WPS). The NAS subscales pertain to anger disposition domains, as linked to an environmental context. The PI assesses self-reported anger intensity in response to provoking situations. Both instruments were developed and validated for use with mentally disordered and normal populations.

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NAS Description and Development

The NAS was first constructed in 1990 as a two-part instrument, which entailed the PI as “NAS Part B.” In its formal publication in 2003, the NAS and PI were designated as separate instruments, and the Anger Regulation subscale was added. In the 2003 revision, a subset of four “attentional focus” items within the NAS Cognitive subscale was replaced by a subset of 4 items concerning “justification.” Some item-wording changes were also made across the instrument.

Scale norms, reliability, and validity were first established for clinical populations in studies with 300 male and female patients, both civil commitment and forensic, at three California State hospitals; 119 male forensic patients in Scotland; 129 male intellectual disability forensic patients in England; and 143 Vietnam combat veterans with posttraumatic stress disorder (PTSD). The WPS standardization sample of 1,546 participants was age stratified (9-84 years) and was obtained from various nonclinical settings across the United States; also added were 171 male offenders in various correctional settings.

NAS Scale Components

NAS Cognitive

The arousal of anger is cognitively mediated, being a function of perception and information processing. A schematic network of memories and meanings centrally influence the experience of anger and its expression. The NAS Cognitive subscale is composed of items operationalizing justification, rumination, hostile attitude, and suspicion.

NAS Arousal

Anger arousal is marked by physiological activation in the cardiovascular, endocrine, and limbic 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.

NAS Behavioral

Implicit in the cognitive labeling of anger is an inclination to act in an antagonistic or confrontative manner. The NAS Behavioral subscale items operationalize impulsive reaction, verbal aggression, physical confrontation, and indirect expression. The NAS Behavioral score is the principal NAS index expected to be associated with violence.

NAS Total

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.

NAS Anger Regulation

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.

Inconsistent Responding Index (INC)

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.

NAS Reliability

In its initial version, the NAS Total had an internal reliability (alpha) of .95 and a 2-week test-retest reliability of .84 in studies with psychiatric patients in the California State hospitals. An independent study with male 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 standardization sample, it was .94. In other studies, the NAS Total alpha was .97 for Vietnam combat veterans, .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.

NAS 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 violence 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 correlations 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 community after hospital discharge. Among combat veterans, 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 treatment received. An important extension in this domain would be for case formulation. Given that anger is now recognized as a dynamic variable associated with violent behavior and that anger treatment efficacy has been demonstrated, the NAS would seem to have value for case formulation as the cognitive, arousal, and behavioral domains lend themselves to identification of the psychological deficits associated with anger dysregulation.


  1. Novaco, R. W. (1994). Anger as a risk factor for violence among the mentally disordered. In J. Monahan & H. J. Steadman (Eds.), Violence and mental disorder: Developments in risk assessment. Chicago: University of Chicago Press.
  2. Novaco, R. W. (2003). The Novaco Anger Scale and Provocation Inventory (NAS-PI) Manual. Los Angeles: Western Psychological Services.
  3. Novaco, R. W., & Taylor, J. L. (2004). Assessment of anger and aggression in male offenders with developmental disabilities. Psychological Assessment, 16, 42-50.

Return to the overview of Violence Risk Assessment in Forensic Psychology.