The final element of the model is the , which recognizes that both the developing person and their environment change over historical time and life course. An individual’s developmental trajectory is shaped by the cumulative history of proximal processes. A child who experiences consistent, warm, cognitively stimulating interactions from infancy will likely have a different developmental outcome than a child whose early proximal processes were characterized by neglect or hostility. However, the chronosystem also allows for change: a sensitive intervention at a later stage (e.g., a mentoring program in adolescence) can alter the trajectory.
For a proximal process to effectively "make a human being human," it must meet specific criteria:
The nested systems of the environment, ranging from immediate settings (family, school) to broad cultural values.
[ MACROSYSTEM: Culture, Laws, Beliefs ] [ EXOSYSTEM: Neighborhood, Media, Workplace ] [ MESOSYSTEM: Interactions between Microsystems ] [ MICROSYSTEM: Family, School, Peer Group, Home ] ( THE PERSON ) The final element of the model is the
The initial focus was heavily structural. It described the environment as a set of nested Russian nesting dolls, moving from the immediate home outward to broad cultural beliefs. Critics noted that this early version treated the developing person somewhat passively.
Behavioral tendencies, such as curiosity, persistence, or impulsivity, which can invite or discourage proximal processes.
The most informative feature of Urie Bronfenbrenner's Making Human Beings Human: Bioecological Perspectives on Human Development (2004/2005) is its shift in focus from the environment alone to as the primary engines of human development . While his earlier work emphasized the "nested circles" of systems, this culminating volume highlights that development occurs through regular, progressively complex interactions between an active individual and their immediate environment. Key Informative Elements However, the chronosystem also allows for change: a
The extent to which these processes occur repeatedly over days, weeks, or generations.
At its core, Bronfenbrenner’s theory argues that human beings are not developed in a vacuum. Instead, development is the result of continuous, dynamic interactions between the developing person and the immediate, surrounding environments.
In collaboration with Stephen J. Ceci and other colleagues, Bronfenbrenner updated the theory. The revised model placed the active, biological person at the center and introduced the PPCT model (Process-Person-Context-Time). This update emphasized that individuals actively shape their environments just as environments shape them. The PPCT Framework: The Engine of Development It described the environment as a set of
: Powerful proximal processes can buffer genetic vulnerabilities and mitigate environmental deficits, serving as the ultimate catalyst for realizing human potential. 2. The Person
This mature theory is defined by the :