Urie Bronfenbrenner, Russian-American psychologist and ecologist (born 1917)

Urie Bronfenbrenner was a Russian-born American psychologist best known for using a contextual framework to better understand human development. This framework, broadly referred to as 'ecological systems theory', was formalized in an article published in American Psychologist, articulated in a series of propositions and hypotheses in his most cited book, The Ecology of Human Development and further developed in The Bioecological Model of Human Development and later writings. He argued that natural experiments and applied developmental interventions provide valuable scientific opportunities. These beliefs were exemplified in his involvement in developing the US Head Start program in 1965. Bronfenbrenner's writings about the limitations of understanding child development solely from experimental laboratory research and the potential for using contextual variability to provide insight into developmental processes was important in changing the focus of developmental psychology.