Socio-emotional dysfunction is a core feature of bipolar disorder (BD) across the lifespan. Recent evidence indicates associations between this atypical functioning and the presence of neurally-based anomalies. This article critically reviews the literature on two types of core socioemotional skills that may represent endophenotypes for BD, with a focus on differences between individuals with BD, both youth and adults, and their typically developing peers. First, it examines studies of social cue perception and interpretation, with an emphasis on behavioral and neural studies of facial expression processing. Second, it shifts to examine behavioral and neural differences in cognitive and behavioral flexibility. Finally, the article summarizes potential future directions for research in this area.