Exposure to traumatic events and experiences: aetiological relationships with personality function

Empirical research has shown that the odds of experiencing traumatic events are influenced by genetic factors and the heritability of trauma exposure varies with the type of trauma. Traumatic events per se are unlikely to be heritable; more likely to be inherited are factors such as personality that influence the person's risk for entering into, or creating, potentially hazardous situations. With data from 406 twin pairs (222 monozygotic and 184 dizygotic twin pairs) from the urban general population, the present study used multiple regression analysis to identify personality variables associated with exposure to trauma, and estimated the degree to which these relationships were mediated by genetic factors. The experience of violent assaultive traumatic events was predicted by antisocial personality traits, specifically juvenile antisocial behavior, self-harming behavior, Psychoticism (e.g. adult antisocial behavior and substance misuse), and being open to new ideas and experiences. Genetic factors were found to partially mediate these relationships as indexed by the genetic correlation coefficient. The values of the genetic correlations were statistically significant and ranged from 0.14 to 0.36, accounting for 5-11 % of the observed correlation between personality and trauma exposure. These findings suggest that heritable personality characteristics explain part of the variance in the likelihood of exposure to some classes of traumatic events. (C) 2003 Elsevier Ireland Ltd. All rights reserved.