In Bronfenbrenner's (1979, 1989) ecological model, individual development occurs through a process of mutual accommodation across multiple interconnected systems. Individuals are embedded in four different, interacting systems: micro system, mesosystem, exosystem, and macro system. The micro system is the innermost system, consisting of people and the immediate settings with which an individual interacts directly. Next, the mesosystem consists of interactions among and between the people and settings (e.g., conversations among coworkers) that comprise the micro system. Moving outward, the exosystem consists of legislation and policies that influence people and settings in the micro- and mesosystems. Finally, all systems are embedded within the macro system— the cultural blueprints of a society. All systems coexist in bidirectional, relational tension; not only do events that occur in each system affect inner systems, but also events in inner systems affect outer systems. For example, a school superintendent who is impressed with a male teacher's after-school mentoring program for male students might alter hiring policies to ensure that male teachers are available to staff similar programs within the district. Thus, individuals are powerful to change their environments as they themselves are changed.
Initially conceptualized as a model of human development, Bronfenbrenner's (1979, 1989) model has been applied to other disciplines, including mental health counseling and prevention, child and family counseling, trainee remediation, and research with immigrant populations. Many authors have argued that attention to the multiple systems that constitute a person's ecology broaden clinicians' and researchers' contextual understanding of the situation and increase the likelihood of effective practice.
The “glass escalator”, in which men experience hastened promotion in nontraditional occupations, is an example of a phenomenon that can be explained using the ecological model. The “glass escalator” is a multi-systemic occurrence that affects men's work lives directly when they are (and/or expect to be) promoted more readily than their female peers. Employers may encourage such promotions at a formal or informal policy level (exosystem). Such promotions affect relationships between the men and their colleagues (micro system) and among their colleagues (mesosystem). Designing research to explore how such promotions affect (a) members of the nontraditional work environment intrapersonal as well as (b) members' interactions with each other and (c) members' interactions with an individual male worker (current colleague and future workers) could capture the complex effects within the workplace that are prompted by the glass escalator.