Bronfenfrenner's Ecological Systems Theory The American psychologist of Russian origin Urie Bronfenbrenner (1917 – 2005) developed the ecological systems theory of human development. This paradigm was presented in The Ecology of Human Development: Experiments by Nature and Design, (1979). Bronfenbrenner proposed that interactions with others and the environment are essential for human development. He described our environment in terms of an “ecological system” that can be divided into four socially organized subsystems, or “environmental layers” (Bronfenbrenner, 1979) that support and aid human growth. They are known as micro, meso, exo, maxo systems and are generally presented as a series of interlocking circles with the individual at the center. Graber, Woods, and O'Connor (2012) reported that the theory is dynamic and bidirectional; that is, one level of the system is affected by the other. Bronfenbrenner continually re-evaluated and made modifications to his theory from its conception in 1979 until his death in 2005, "re-evaluating, revising and extending – and even renouncing – some of the conceptions outlined in [the] 1979 monograph". » (Bronfenbrenner, 1989, p. 187). Bronfenbrenner and Morris (1998) documented the importance of time on human development, which has become the fifth or outer layer, the chronosystem. For the purposes of this answer I will refer to the individual as a child, but it should be noted that any elderly individual can be the focus of the theory. The child's immediate environment in which he or she operates is known as the microsystem (Bronfenbrenner, 1979). ), and includes physical, social and psychological factors (Swick and Williams, 2006). This system includes people who have a direct relationship with the child. ......middle of paper ......we talk with people (family, friends and teachers) about child development. It reveals how the environments a child lives in, such as child care or low socio-economic communities, can make a difference in a child's well-being. Ecological systems theory, however, does not take into account genetic factors that may influence a child's development. . It focuses on contextual factors rather than individual factors. It does not provide in-depth developmental mechanisms and does not encourage, especially in early adolescence, analyzes of children's interactions with peers, schools, and cultures that do not come from their parents (Goodnow, 1994). The ecological system of human development by Urie Brofenbrenner (1979), is a model widely used in the fields of health, child development and education. It represents the dynamic relationship between biological and social environments.