This study investigated instrumental and expressive beliefs about aggr
ession, and their association with self-reported aggression, among mal
e (N = 62) and female (N = 47) prisoners serving sentences in closed p
risons in the North of England. Instrumental but not expressive belief
s were strongly correlated with measures of aggression. Expressive bel
iefs were significantly higher among females than mates, but unlike pr
evious findings, there were no significant sex differences in instrume
ntal beliefs or in physical aggression. However, age was significantly
negatively correlated with instrumental beliefs, physical aggression,
anger and hostility, Those convicted for violent offences showed sign
ificantly higher scores for physical aggression and anger, but lower s
cores for expressive beliefs. The results provide both similarities an
d contrasts with previous findings for student samples. (C) 1997 Wiley
-Liss, Inc.