Attachment theory is based on Bowlby's work on the connections between maternal loss or deprivation and personality development and on Ainsworth's interest in security theory. Their separate and joint work is reviewed, along with that of other theorists and researchers whose work influenced them or was influenced by them. (LB)

Reviews Gibson's contributions to the domain of perceptual learning, including her classic experiment concerning the perception of scribbles. Discusses Gibson's research on differentiation and the links between perception and learning, the status of her research and ideas, and her experimental approach. (BG)

Social learning theory is evaluated from a historical perspective that goes up to the present. Sears and others melded psychoanalytic and stimulus-response learning theory into a comprehensive explanation of human behavior. Bandura emphasized cognitive and information-processing capacities that mediate social behavior. (LB)

Bayley's major contributions to developmental psychology are reviewed. These include her concern with measurement and methodology and her early anticipation of such topics as behavior genetics. Her work in such areas as androgyny and body build, motor and mental development, and maternal and child behaviors is summarized. (LB)