Recent literature has documented the increasing prevalence of narcissism. Narcissism fascinates psychologists and the public alike. Normal (i.e., sub-clinical) narcissists view themselves as action superheroes and boast about their superior competence. They embed agentic narcissism. Recent research, however, has indicated that some narcissists see themselves as quaint saints and brag about their superior kindness. They embed communal narcissism. We engage in an investigation of agentic and communal narcissism by combining behavior genetics and social neuroscience, in an effort to differentiate and clarify these two constructs. For the genetic part, we design a twin study to identify the heritability of agentic and communal narcissism by comparing monozygotic twins with dizygotic twins. Moreover, we expect to find that the genetic factors influencing agentic narcissism correlate with those influencing communal narcissism only to a minimal extent, suggesting divergent genetic bases underlying agentic and communal narcissism. For the neural part, we plan to study intrapersonal self-positivity and interpersonal defensiveness by functional magnetic resonance imaging (fMRI). We expect to observe that agentic and communal narcissism moderate the neural representations of narcissistic behaviors through dissimilar ways.