Data are presented from families of monozygotic twin pairs which give evidence of genetic variance on the Block Design Test, a nonverbal measure of intelligence. Analyses of genetic and environmental effects on behavior are possible with this kind of information. (SA)

The hypothesis of less direct interaction between hemispheres in young children was supported by a behavioral test. Fabric samples were compared with either the same hand (same hemisphere) or with opposite hands (between spheres). (Author/HM)

A test is described in which three psychotropic drugs were evaluated for their effects on pregnant rats. Behavioral changes are given. (SA)

This article reviews some recent technical progress in the social sciences and three frontier areas including evolutionary theory as related to sociobiology, the theory of human rational choice, and cognitive science. These areas offer explanations for broad areas of human behavior. (Author/SA)

Through the use of learned symbols, two chimpanzees accurately specified 11 foods by name to one another when the food item's identity was known by only one and requested specific food of one another by name. Requests resulted in cooperative and reciprocal symbolically mediated food exchange. (Author/MA)

Described is an ongoing study of monozygotic and dizygotic twins, separated in infancy and reared apart. Discussed are the procedures and results of this study with interpretations of the results. The effects of parenting, education, and other interventions are considered. (CW)