A fast-growing area of research is now aimed at understanding the biological bases of political behavior. This chapter reviews what is known about the genetic underpinnings of political behavior including political ideology, partisanship, political interest, knowledge, and participation. For each, it highlights what is known, what is largely speculative, and what questions need to be addressed. The findings raise new questions about our understanding of social and, more broadly, environmental influences on behavior. There is a critical need for better theoretical models and greater attention to the mechanisms through which genetic and environmental factors interact. As such, this research area is particularly promising for political psychology.