Ecological systems theory, also known as ecological perspective or bioecological theory, is a psychological framework developed by Urie Bronfenbrenner. It emphasizes the complex interplay between individuals and their environment, recognizing that human development is influenced by multiple levels of environmental systems.

Key concepts of ecological systems theory include:

1. Microsystem: The microsystem refers to the immediate environment in which an individual lives and interacts on a daily basis. It includes settings such as family, school, peer group, and neighborhood. The microsystem is where direct interactions and experiences occur, and it plays a crucial role in shaping an individual’s development and experiences.
2. Mesosystem: The mesosystem encompasses the connections and interactions between different microsystems in an individual’s life. For example, the relationship between a child’s family and school or the interaction between peer groups and community organizations. The mesosystem highlights the importance of understanding how experiences in one setting influence and are influenced by experiences in other settings.
3. Exosystem: The exosystem involves settings or contexts that indirectly influence an individual’s development, even though the individual may not directly participate in them. Examples of the exosystem include the parent’s workplace, community services, mass media, and government policies. These external environments can have significant effects on the individual’s experiences and opportunities, mediated through their immediate microsystem.
4. Macrosystem: The macrosystem refers to the broader cultural, societal, and ideological contexts in which individuals are embedded. It includes cultural values, norms, beliefs, laws, and social structures that shape the experiences and opportunities available to individuals. The macrosystem influences the functioning of all other systems and plays a fundamental role in shaping human development.
5. Chronosystem: The chronosystem involves the dimension of time and how environmental systems change over time. It recognizes that individuals and their environments are dynamic and evolve over the lifespan. Changes in family structure, societal events, historical trends, and personal life transitions can have profound effects on individuals’ development and experiences.

Ecological systems theory emphasizes the dynamic interplay between individuals and their environments, highlighting the bidirectional influences and interactions that shape human development. It emphasizes the importance of considering multiple levels of environmental systems and their cumulative effects on individuals’ experiences and outcomes.

This framework has been widely applied in various fields, including developmental psychology, education, social work, and public policy. It informs interventions and programs aimed at promoting positive development and addressing issues such as poverty, inequality, and social injustice by recognizing the importance of environmental influences on individuals’ lives.