This volume contains 15 papers that were delivered at a conference on environmental influences on behavior, a conference sponsored by The Rockefeller University and the Russell Sage Foundation. Topics deal with specific social- and physical-environmental effects on behavior, such as nutritional deficiencies and mental development and functioning; the effects of social deprivation on intellectual performance and social behavior among human and infrahuman species; and the influence of cultural deprivations on human cognitive development and organization.