Studies in the area of locus of control have tended to neglect the familial antecedents of this variable, particularly among ethnic minorities, and to overlook the role of teachers in the development of children's locus of control beliefs. Moreover, studies have not examined the simultaneous contribution of parents' and teachers' socialization behavior to children's locus of control scores. The relationship of the locus of control orientations of Mexican- and Anglo-American children were examined to compare their descriptions of their mothers', fathers', and teachers' socialization practices. Results showed significant variations in the relation of parents' and teachers' socialization behaviors to children's locus of control scores as a function of both children's and adults' sex and ethnicity, as well as the nature of the locus of control dimension. In addition, teachers' socialization behavior showed a more pervasive relation to children's locus of control scores than parental behavior. (Author)