Darwin's weak influence on developmental psychology is traced. It is explained by (1) developmentalists' commitment to an ideology of meliorism; (2) conceptual issues relating to ontogeny and phylogeny; and (3) methodological problems. Suggests that developmentalists use evolutionary theory as a heuristic for structuring new research. (BC)

James Baldwin's ideas, such as that of a genetic science, and their influence on later theorists such as Piaget, Vygotsky, and Kohlberg, are described. The further Baldwin moved from the study of infancy, the more speculative and the less empirically verifiable became his ideas. (BC)