Impulsive/Premeditated Aggression Scale

The Impulsive/Premeditated Aggression Scale (IPAS) is a 30-item self-report questionnaire. Half of the items describe impulsive aggression and half the items describe premeditated aggression. Aggressive behavior has traditionally been classified into two distinct subtypes, impulsive or premeditated. Impulsive aggression is defined as a hair-trigger aggressive response to provocation with loss of behavioral control. Premeditated aggression is defined as a planned or conscious aggressive act, not spontaneous or related to an agitated state. The IPAS is designed to characterize aggressive behavior as predominately impulsive or predominately premeditated in nature. Those subjects who clustered on the impulsive factor showed a broad range of emotional and cognitive impairments; those who clustered on the premeditated factor showed a greater inclination for aggression and antisocial behavior.