Background: Accumulating data from animal and human studies indicate that the prenatal environment plays a significant role in shaping children's neurocognitive development. Clinical, epidemiologic, and basic science research suggests that two experiences relatively common in pregnancy--an unhealthy maternal diet and psychosocial…

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)