Faculty Advisor

Lisabeth F. DiLalla


The purpose of this project was to examine the relations between parent personality and child externalizing behaviors (e.g., acting out, aggression). To do this, parent personality, child temperament, and externalizing behaviors in children were examined. To further understand the role of genetics vs. environmental influences, identical (MZ; monozygotic) twins and fraternal (DZ; dizygotic) twins were compared. This allowed the percentage of the relation that was due to shared environment between the parent and the child versus the percentage of the relation that was due to genetic commonalities between the parent and child to be examined. For this study, archival data from twins aged 5 to 10 years and their parents were used. Additionally, supplemental data from families that were missing data from one age were collected. Several questionnaires were used to assess the personality of the parents, as well as the temperament and behaviors of the children. It was found that parent personality was not related to externalizing behaviors in children, but childhood temperament, specifically adaptability, was related to externalizing behaviors in children. Furthermore, it was found that parent personality was related to childhood temperament, which could indicate an indirect link between parent personality and externalizing behaviors via child temperament. Lastly, it was found that these relations were in part due to shared genes between the parents and the children, indicating that genes also play a large role in the behaviors of children and that it is not only the environment in which they are raised that is important.