This study discusses the behavior of the females of the parasitic wasp Nasonia vitripennis, which adjust the sex ratio of their broods according to whether or not they are the first or second wasp to parasitize a host. The results provide a quantitative test of sex ratio theory. (Author/SA)

An interactive, biosocial model of early hominids presents evidence that physical sex differences are not the basis for the sexual division of labor as is commonly believed. Production (the deliberate collection and distribution of food) developed among early hominids as a prerequisite for survival. Although the population appears to have had…

Examines perspectives on family influences on child development. Maintains that genetic and biological factors and parental actions/attitudes make important contributions to individual differences. Draws on research on gender differences and conduct disorders to illustrate that parental influence on individual differences within cultures has been…

Examined ability of individuals biologically predisposed to poor spatial skills to capitalize on opportunities to develop these skills. Found that for girls with brothers, those from all right-handed families had lower mental-rotation scores than did others. Among children participating in mental-rotation-type activities with their brothers,…

Sex differences in cerebral organization and functioning, and the apparent superiority of males in spatial ability are examined in this paper. Attention is given to several kinds of cognitive and perceptual tasks in which sex differences in spatial ability have been shown to exist; among these are tasks involving: (1) recall and detection of…

It is difficult to make progress in the study of emotions and emotional development if the meanings assigned to central constructs vary widely across investigators. This book clarifies and synthesizes the different ways in which emotion researchers approach fundamental questions about the nature of emotion and emotional development. Theorist and…