The study found that children who exhibited the highest levels of AB and CU traits also experienced higher levels of negative parental feelings and harsh parental discipline. This pattern held before and after controlling for gender and the family's socioeconomic status. Findings on child-driven effects on parenting characteristics, however, indicated a reciprocal effect, i.e., children's conduct problems (AB and CU) elicited negative parental feelings and parental efforts to suppress children's problem behaviors. Identification of the factors underlying children's AB and CU that evoke negative parental feelings and behaviors toward the children is still an open question; however, results from one recent study indicate that genetically influenced AB evokes conflict in the parent-child relationship. This suggests a gene-environment process that underlies negative parent-child interactions associated with high levels of AB and CU in children. To date, there has been no published study that has focused on identifying genes linked to CU traits. Study data came from the 1994 and 1995 birth cohorts of the Twins Early Development Study, a large population-based longitudinal study of twins born in England and Wales. The final sample consisted of 4,430 twins (53 percent boys). Only same-sexed twins were included in this study. Teachers provided ratings of CU and AB traits when the twins were 7 years old. Parental feelings toward children were assessed when the children were ages 3 and 4, using the Parent Negativity Scale of the Parent Feelings Questionnaire. Parental harsh discipline was assessed at ages 3 and 4 based on two questionnaire items adapted from a semistructured interview. Information on children's symptoms of conduct problems and hyperactivity was obtained from parent reports when the twins were 3 years old. 3 tables and 46 references