While previous research has investigated the influence parenting styles have on child behavior, there has not been consistent findings on how child behavior in return influences parenting. This study goes beyond the literature by examining bidirectional influences of combined dyad for emotional availability and early problem behaviors (composited across 12 and 30 months) predicting parental warmth, authoritarian parenting, internalizing, externalizing and ADHD symptoms at age eight. This study also examined whether genetic or environmental factors were driving these behaviors. Participants were from the ongoing Arizona Twin Project (N=340 twin children). 25% of the twins were monozygotic, 35% were same-sex dizygotic, and 35% were opposite-sex dizygotic twins. Preliminary correlations showed bidirectional effects between early emotional availability, problem behaviors and parental warmth, authoritarian parenting, internalizing, externalizing and ADHD symptoms at age eight; however, once twin dependence and covariates were controlled for, the bidirectional effects were no longer significant. One important finding emerged: early problem behaviors were predictive of later problem behaviors at eight years. The study also found that externalizing and ADHD symptoms were more heritable than emotional availability, early problem behaviors, and internalizing symptoms. Therefore, interventions should be developed addressing the environmental influences that contribute to early problem behaviors.