Critically reviews literature relevant to the hypothesis that a major X-linked gene determines spatial ability in man. It is concluded that belief in the validity of the hypothesis is unfounded. (Author/SS)

Estimates the extent to which heredity influences perceptions of childhood family environment in a sample of 58 monozygotic and 46 dizygotic pairs of adult twins who were reared apart. The data confirm the importance of genetic factors in some, but not all, measures of family environment. Environmental influences were more important than genetic…

Posits that an evolutionary perspective can unite the study of the typical development for and individual variation within a species and that environments within the normal range for a species are required for species-normal development. Individual differences in children reared in normal environments arise primarily from genetic variation and…

Examined low interrater agreement by decomposing common and unique variance among parent, adolescent, and observer reports of parental warmth and negativity into genetic and environmental factors. Model-fitting analyses findings generally supported predictions for warmth and negativity at Family and Individual levels. At the Social level, genetic…

Key components of human behavioral genetics and Sandra Scarr's work of the past two decades are critically reviewed based on scholarship in animal neuropsychology and clinical and educational psychology. Scarr's opinion that interventions to enhance intellectual development are ineffectual for children from abuse- and neglect-free backgrounds is…

Takes the position, contrary to that of Sandra Scarr, that the details of socialization patterns are crucial to an understanding of normal and deviant development. Research is cited to support the argument that better than adequate parenting optimizes the development of both normal and vulnerable children and that parents' belief in their own…