FIGURE 1.3 The Ecological Model Each person is affected by interactions among overlapping systems, which provide the context of development. Microsystems—family, peer groups, classroom, neighbourhood, house of worship—intimately shape human development. Surrounding and supporting the microsystems are the exosystems— external networks, such as local educational, medical, employment, and communications systems—that influence the microsystems. Influencing both of these systems is the macrosystem, which includes cultural patterns, political philosophies, economic policies, and social conditions. Mesosystems refer to interactions among systems, as when parents and teachers coordinate to educate a child. Bronfenbrenner eventually added a fifth system, the chronosystem, to emphasize the importance of historical time.