Social brain science is an emerging field that encompasses researchers who combine approaches of evolutionary psychology, social psychology, and neuroscience to study human behavior. This talk focuses on how such an approach can provide new insights into the human sense of self.  A unitary sense of self that exists across time and place is a central feature of human experience, at least for most people. Understanding the nature of self—what it is and what it does—has challenged scholars for many centuries. The use of neuroimaging has demonstrated that information relevant to self may receive special processing by the brain, and it may allow us to distinguish cognitive from affective components of self. Behavioral and imaging data will also be presented that support a functional account of self-esteem; namely that low self-esteem may reflect a heightened sensitivity to the possibility of social rejection.  The overall goal of the talk is to provide examples of how social neuroscientists are attempting to examine some of the most fascinating and previously intractable aspects of the essential social nature of human life.