An extensive literature exploring a range of peer influences on both academic and non-academic outcomes continues to produce contradictory evidence regarding the existence and magnitude of peer effects. Our results provide no evidence of peer effects in models where peer academic ability is measured in the aggregate. However, models that control for own-gender and other gender peer performance identify strong, positive, and statistically significant male peer influence on male students. In contrast, females are unresponsive to either male or female peer average academic rating. The results highlight the possibility that significant own gendered effects for males may be masked by insignificant effects in the aggregate. (Contains 3 figures and 9 tables.)