Previous research has suggested that bipolar disorder is characterized by a state-dependent decrease in the ability to recognize facial affect during mania. It remains unclear, though, whether people who are only vulnerable to the disorder show these changes in facial affect recognition. It is also unclear whether minor shifts in mood affect the recognition of facial emotion. Thus, this study examined the effects of positive mood induction on the facial affect recognition of undergraduates vulnerable to mania. Fifty-two undergraduates completed the Hypomanic Personality Scale, and also completed a measure of their ability to recognize affect in pictures of faces. After receiving false success feedback on another task to induce a positive mood, they completed the facial affect recognition measure again. Although we expected to find a relationship between higher Hypomanic Personality Scale (HPS) scores and an impaired ability to recognize negative facial affect after a positive mood induction, this was not found. Rather, there was a significant interaction between HPS scores and happiness level, such that individuals with higher scores on the HPS who also reported higher levels of happiness were particularly adept at identifying subtle facial expressions of happiness. This finding expands a growing literature linking manic tendencies to sensitivity to positive stimuli and demonstrates that this sensitivity may have bearing on interpersonal interactions.