Summary

During the mid-20th century, the study of human development in the United States underwent significant expansion as support for scientific approaches solidified and methods and research topics grew. Inside the field, tensions between contrasting theoretical approaches and differing views on what determines growth and change (e.g., the perennial nature vs. nurture debate), fueled a proliferation of studies on physical growth and motor development, IQ, and personality. Lois Barclay Murphy, for example, challenged the emphasis placed on aggression and conflict in personality studies to include evidence of the early appearance of empathy and altruism in the young child, contradicting the outlook popularized by behaviorist John Watson in the 1920s. While hereditarian views of intelligence were dominant in the early part of the century, research by Marie Skodak Crissey and others soon challenged that perspective and pushed the field to develop more interactive models of heredity and environment. Skodak Crissey, for example, documented the powerful impact of adoption versus institutional care on measures of intelligence, demonstrating the mutability of intelligence as a result of environmental changes.

In addition, the field expanded during the mid-century period (which is here defined as approximately 1925 to 1960) from studies of the infant and child to adolescents and development over the lifespan, including longitudinal studies like the Berkeley Growth Study, initiated in 1928 and headed by Nancy Bayley, and Lewis Terman’s long term study of gifted children. While historical accounts emphasize the contributions of a small number of male psychologists (such as Watson, Arnold Gesell, and Terman), women entered the field in large numbers and made landmark contributions during this period, often challenging and undermining orthodoxies and motivating the more complex picture of development dominant today. Among the women making contributions were Marie Skodak Crissey (1910–2000), Nancy Bayley (1899–1994), and Lois Barclay Murphy (1902–2003).