Title: Mental Representations of Attachment in Twins: A Study of Monozygotic Female Pairs Concordant and Discordant for Abnormally Aggressive Behavior
Name: John N. Constantino
Washington University School of Medicine
660 South Euclid Avenue
Campus Box 8134, Saint Louis
Missouri 63110
(314)747-6772
constantino@psychiatry.wustl.edu
Year: 2001, 2002
Type: Research Grant
Summary: Previous research has suggested a link between the quality of early social relationships and the development of aggression. This association is most pronounced when children are maltreated, but the mechanism by which social experience influences social developmental outcome is poorly understood. One possible mechanism is that relationship-relevant experiences are incorporated into an internal working model (mental representation) of social relationships that is used on a moment-to-moment basis in the context of social interaction. Most previous studies of attachment characteristics and psychopathology have not been able to control adequately for the possibility that any observed association might be due to genetic influences that independently affect both. This study represents an initial step in elucidating the genetic structure of mental representations of attachment (MRA) and the extent to which MRA, in turn might mediate the development of abnormally aggressive behavior. Specifically, this study examines concordance in attachment status among pairs of female adolescent monozygotic twins, as well as their non-twin siblings (NTS) and relates attachment classification to several parameters of antisocial development.

The Adult Attachment Interview (AAI) has been completed on 40 pairs of identical female twins, concordant or discordant for a presence or absence of conduct disorder. The AAI is an established, one-hour audiotaped interview that assesses an adult or adolescent subject's current state of mind with respect to relationships. It inquires about the subject's own early relationships with caregivers, and about previous experience with separation, loss, or trauma. It classifies an individual's mental representation of attachment into one of four categories (secure-autonomous, insecure-dismissing, insecure-preoccupied, insecure-unresolved), which correspond to the four attachment categories used to classify parent-infant dyads in the Ainsworth Strange Situation.

The results to date indicate that mental representations of attachment are substantially influenced by shared environmental influences and are associated with current levels of aggressive behavior, as well as histories of arrest and symptoms of conduct disorder. These findings support the notion that mental representations of attachment are, in large part, a function of environmental factors, and that they may play a mediating role in the development of abnormally aggressive patterns of behavior. Interventions that promote the development of secure parent-child relationships early in life may help prevent the development of abnormally aggressive patterns of behavior.