TUNMER, WILLIAM E. The Acquisition of the Sentient-Nonsentient Distinction and Its Relationship to Causal Reasoning and Social Cognition. CHILD DEVELOPMENT, 1985, 56, 989-1000. In considering the question of how the development of social cognition may be related to nonsocial cognition, Gelman and Spelke suggest that what may develop over childhood is a clear understanding of the distinction between the social and physical principles that govern social and nonsocial events, respectively. 1 such principle is that social events involve the actions of sentient beings, whereas physical events do not. To explore this possibility further, 2 tasks were administered to 48 4-, 5-, 6-, and 7-year-old children. In the first task children were asked to judge the acceptability of sentences, half of which were semantically anomalous ones violating either the animate-inanimate or sentientnonsentient selectional restriction. In the second task children were asked to explain the observed effects of manipulations of familiar objects and the occurrence of common celestial and meteorological events that varied in the type of logical conditionship relation involved. The results indicated that the acquisition of the sentient-nonsentient distinction occurs later in development than the animate-inanimate distinction, that children use naturalistic or nonnaturalistic explanations depending on the logical nature of the events in which the objects are involved rather than familiarity with the objects themselves, and that children's ability to provide naturalistic explanations of physical phenomena may be related to their acquisition of the sentient-nonsentient distinction.