Urie Bronfenbrenner has had a profound, enduring, and generative influence on our understanding of human development. As a teacher, he has influenced generations of Cornell University students. Many of his students have gone on to earn distinction as scholars in their own right. His introductory course in human development was so popular that only Cornell's concert hall could hold all the students, and some years they spilled over into a second lecture hall connected via closed-circuit TV. Among the many thousands of students who took that course, some who became social scientists credit him with teaching them how to design research when they were freshmen. His teaching extends to detailed critiques on work in progress that he generously provides to colleagues and young scholars on campus and around the world.
In addition to designing creative studies himself, Bronfenbrenner has continually discovered gems hiding in data collected by others. The most impressive of his reinterpretations would today be called a meta-analysis of research on parental practices. Taking a set of findings that others had found inconclusive at best, Bronfenbrenner (1958) separated subjects by the nature of the father's employment—manual and non-manual (admittedly crude but the best that the data allowed). He also distinguished studies according to the age of the children. Finally, he ordered the published studies by the dates when the data had been collected. This more differentiated analysis revealed a clear historical trend toward greater permissiveness, with middle-class parents leading the way. On a much smaller scale, but similarly impressive as an intellectual feat, Bronfenbrenner extracted from a study of low-birth-weight infants (Drillien, 1964) the complex and theoretically important finding that the impact of mothers' responsiveness (on an index of behavior problems at age 4) varied with family social class and with the severity of low birth weight. In brief, maternal responsiveness reduces problem behavior; it has its largest impact on children in the lowest social class and, within that class, on those of normal birth weight (Bronfenbrenner & Morris, 1998).
The achievement for which he is best known is systematizing and communicating the way of thinking that led to these insightful interpretations. Known by the title of his 1979 book, The Ecology of Human Development, this way of thinking has two main axes. One, to which the book is primarily devoted, applies to the environment or the contexts in which development occurs. Bronfenbrenner conceives of that environment as a hierarchy of four systems, nested one inside the other like Russian dolls.
The microsystem is the immediate setting that includes the developing person, for example, the home or classroom, and what happens in that setting. Key aspects of a child's microsystem are the activities that the child engages in over time, the relationships he or she has with significant others, and the roles the child plays in that setting. Influenced by the Soviet psychologist Vygotsky, Bronfenbrenner is especially interested in the joint activities that occur between adults and children that contribute to the ...