Social scientists have predicted that individuals who occupy socially privileged positions or who have conservative political orientations are most likely to endorse the idea that genes are the root cause of differences among individuals. Drawing on a nationally representative sample of the US population, this study examines belief in the importance of genes for understanding individual differences in a series of broad domains: physical illness, serious mental illness, intelligence, personality, and success in life. We also assess whether the belief that genetics are important for these outcomes is more common among those in relatively advantaged positions or among those who are more politically conservative. Finally, we consider whether such beliefs predict attitudes toward genetics-related social policies. Our analyses suggest that belief in the importance of genetics for individual differences may well have a substantial effect on attitudes toward genetics-related policies, independent of political orientation or other measures. Our study identifies high levels of endorsement for genes as causes of health and social outcomes. We describe a cultural schema in which outcomes that are "closer to the body" are more commonly attributed to genetics. Contrary to expectations, however, we find little evidence that it is more common for whites, the socioeconomically advantaged, or political conservatives to believe that genetics are important for health and social outcomes. (Contains 5 tables and 9 footnotes.)