SIBLING INTERACTION AND SELF-REPORTED DELINQUENT BEHAVIOR: A STUDY OF 265 TWIN PAIRS

The relationship between the quality of twins' mutual attachment and delinquency is examined in a study of 265 twin pairs. It is predicted that twins with stronger mutual attachments will have lower rates of delinquent behavior. Contrary to this prediction, twins' mutual attachment (that is, the frequency with which the twins saw each other in teenage activities) is found to be unrelated to delinquent behavior. The twins often cooperated, however, in their delinquent acts: 61% of the girls and 79% of the boys reported committing one or more delinquent acts with their twins. In accord with social control theory, social bonds (normlessness, perceived parental acceptance-rejection, and value placed on academic achievement) are strongly associated with delinquent behavior. Except for male DZ twins, however, these same variables are only weakly associated with twins' mutual attachments. A behavioral genetic analysis of the social bonds indicate both genetic and specific environmental components to their variation but fail to show evidence of a shared environmental component. Implications of these findings are discussed.