SIBLING INTERACTIONS, SELF-REGULATION, AND CYNICAL HOSTILITY IN ADULTMALE TWINS

Chronic hostility is associated with increased vulnerability to seriou s physical illness, making developmental influences on this trait impo rtant. We used the Structural Analysis of Social Behavior (SASB) model to examine retrospective descriptions of twin interactions during chi ldhood in a sample of 48 adult male twin pairs. Consistent with previo us research on parental behavior col relates, self-reported hostility as measured by the Cook and Medley Ho scale was associated with descri ptions of the twin's behavior as hostile, controlling, and neglecting. Consistent with the SASB principle of introjection, hostility was als o associated with self directed hostility and neglect. Thus, a develop mental perspective not only describes possible social contexts involve d in the emergence of this trait, but also suggests possible psycholog ical underpinnings. Implications for models of hostility and health ar e discussed.