Table 1.

Validation studies of Impulsive/Premeditated Aggression Scale (IPAS).

Reference	Sample			Mean agea	Principal aggression	Aggression measures	Internal consistencyb		Total explained variancec
	n	Type	Origin				IAd	PMe	IA	PM
Stanford et al. (2)	93 men	Physically aggressive men	Community	35.9	86% physical assault	LHAQf, BPAQg, AIh	0.77	0.82	16.56	14.03
Kockler et al. (35)	86 men	Prisoners	Inpatient Forensic hospital	38	83% convicted for violent crimesi, 37% non-guilty by reason of insanity	nsj	0.81	0.72	20	13
Conner et al. (36)	61 women, 60 men	Patients in treatment for opiate dependence	Outpatient Psychiatric Service	41.9	ns	LHAQ, BPAQ	0.74	0.75	ns
Mathias et al. (37)	24 girls, 42 boys	Adolescent s with conduct disorder	Community	14.5	ns	LHAQ, BPAQ	0.82	0.78	18.5	15.6
Stanford et al. (38)	113 men	Men convicted of domestic violence	Community	36	Domestic violence	LHAQ	0.75	0.86	ns
Haden et al. (39)	213 women, 127 men	Students	Community	19.06	ns	BPAQ	0.77	0.81	24	12
Kuyck et al. (40)	149 men, 70 women	Prisoners	Prison	50% between 25 and 39	75% convicted for violent crimes	ns	0.93	0.90	ns
Chen et al. (41)	389 women, 262 men	Students	Community	26.1	ns	BPAQ	0.70	0.66	12.9	11.9
Romans et al. (42)	114 women, 49 men	Psychiatric patients	Outpatient Psychiatric Service	25.8	ns	OASk	0.85	0.76	23.3	10.1

^aYears.

^bCronbach’s alpha.

^c%.

^dImpulsive aggression factor.

^ePremeditated Aggression factor.

^fLifetime History of Aggression.

^gBuss Perry Aggression Questionnaire.

^hAggression Interview.

ⁱAggravated assault, battery on a law officer, sexual assault, murder, armed robbery, attempted murder, and manslaughter.

^jNot specified.

^kOvert Aggression Scale.