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Psychiatry Research 86 1999 41᎐57
Etiology of the impulsivityraggression relationship:
Genes or environment?
Alesha D. Seroczynski
a,
U
, C.S. Bergeman
a
, Emil F. Coccaro
b
a
Department of Psychology, Uni
¨
ersity of Notre Dame, 118 Haggar Hall, Notre Dame, IN 46556, USA
b
Clinical Neuroscience Research Unit, Department of Psychiatry, Medical College of Pennsyl
¨
ania at Eastern Pennsyl
¨
ania
Psychiatric Institute, 3200 Henry A
¨
enue, Philadelphia, PA 19129, USA
Received 6 October 1998; received in revised form 9 December 1998; accepted 12 January 1999
Abstract
Genetic and environmental influences on the phenotypic relationship between the Barratt Impulsiveness Scale and
the aggression scales from the Buss᎐Durkee Hostility Inventory in adult males were examined. This study used 182
pairs of male MZ twins and 118 pairs of male DZ twins from the Vietnam Era Twin Registry. Phenotypic
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relationships between the measure of impulsivity and subscales of the measure of aggression direct assault, verbal
.
assault, indirect assault, and irritability ranged from 0.22 to 0.51. Genetic and environmental mediation of the
phenotypic relationship between impulsivity and aggression were approximately the same for all four models.
Multivariate model-fitting analysis indicated that irritability and impulsivity had a larger phenotypic relationship, as
well as a greater portion of shared genes and environment than the other three subscales of aggression. This
suggests, for example, that there are more overlapping genetic and environmental influences accounting for the
relationship between irritability and impulsivity than between direct assault and impulsivity. The effects of such
findings on our understanding of impulsive aggression are discussed. ᮊ 1999 Elsevier Science Ireland Ltd. All rights
reserved.
Keywords: Impulsivity; Aggression; Behavior᎐genetic; Twins
U
Corresponding author. Tel.: q1 219 631 5373; fax: q1 219 631 8883; e-mail: alesha.d.seroczynski.1@nd.edu
0165-1781r99r$ - see front matter ᮊ 1999 Elsevier Science Ireland Ltd. All rights reserved.
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