Locus of control (LOC) is related to many aspects of human behavior, yet relatively little is known about what factors in early childhood may dispose a child to develop an internal or external LOC orientation. Data from a British epidemiological, longitudinal, cohort study of 12,463 children and their mothers were used to identify, from a wide range of potential explanatory factors, those having the strongest independent effects on LOC orientation. Socioeconomic status, non-authoritarian parenting style & attitudes, and child activities were hypothesized as and found to be major contributory factors in the model. Though marginal gender differences were found in the antecedents of LOC development, the analyses for boys and girls were generally very similar.