American psychologist Urie Bronfenbrenner was critical of previous theories of child development. He argued that studies of children in unfamiliar laboratory environments with one other person, usually a stranger, were ecologically invalid (See Mary Ainsworth’s 1970 experiment of the ‘Strange Situation’).

Bronfenbrenner (1974) claimed most earlier studies were ‘unidirectional’, meaning that the laboratory studies observed the influence of A on B (e.g. a stranger/mother with a child), rather than looking at the possible influence of the child on the stranger/mother, or any other third party’s influence.

Bronfenbrenner maintained that these laboratory features of research are not characteristic of environments that children actually live and develop in.

Bronfenbrenner’s (1974) perspective has some resemblance to the works of Albert Bandua’s social learning theory and Lev Vygotsky’s sociocultural theory in which the environment is explicitly or implicitly considered as a crucial mechanism in development.

Nested systems: Urie Bronfenbrenner’s Key Concept

Bronfenbrenner’s concept depicts four ecological systems which an individual will potentially interact with, each nested within the others. Viewed from the innermost system outwards, Bronfenbrenner’s model illustrates the following systems:

Bronfenbrenner's Ecological Systems Theory

1. Microsystem — This is the first, and closest, layer of the nested systems which encompasses an individual’s human relationships, interpersonal interactions and most immediate surroundings. Thus depicting the relationship between an individual child and his/her parents, siblings, and school environment.

2. Mesosystem — Moving outwards, the second layer surrounding the microsystem encompasses the different interactions between the characters contained within the microsystem. This could include, for instance, the relationships between a child’s family and their school teachers. For any interaction to qualify as part of the mesosystem, it has to be a direct interaction between two features of the bio-ecological system which influence the development of the individual child.

3. Exosystem — The third layer is the exosystem which incorporates elements of the bio-ecological systems which do not directly affect the child, but may have an indirect influence. For instance, if a parent were to be made redundant or have their working hours reduced, this would then indirectly affect their child in that such events would create parental stress and reduce the family income.

4. Macrosystem — The outermost, “macro” layer of the bio-ecological model encompasses cultural and societal beliefs, decisions and actions which influence an individual child’s development. This might include, for example, religious influences or parliamentary legislation.

Bronfenbrenner’s bio-ecological approach helps practitioners to consider the true balance of influences which are likely to play a part in the development of any young child.

5. The Chronosystem- The chronosystem includes the transitions and shifts in one's lifespan. This may also involve the socio-historical contexts that may influence a person. One classic example of this is how divorce, as a major life transition, may affect not only the couple's relationship but also their children's behavior. According to a majority of research, children are negatively affected on the first year after the divorce. The next years after it would reveal that the interaction within the family becomes more stable and agreeable.

The Bioecological Model

It is important to note that Bronfenbrenner (1994) later revised his theory and instead named it the ‘Bioecological model’.

Bronfenbrenner became more concerned with the proximal processes of development, meaning the enduring and persistent forms of interaction in the immediate environment. His focus shifted from focusing on environmental influences to developmental processes individuals experience over time.

‘…development takes place through the process of progressively more complex reciprocal interactions between an active, evolving biopsychological human organism and the persons, objects, and symbols in its immediate external environment.’ (Bronfenbrenner, 1995).

Bronfenbrenner also suggested that in order to understand the effect of these proximal processes on development, we have to focus on the person, context and developmental outcome as these processes vary and affect people differently (Bronfenbrenner & Evans, 2000).

Value of the Theory

This theory, published in 1979, has influenced many psychologists in terms of the manner of analyzing the person and the effects of different environmental systems that he encounters. The ecological systems theory has since become an important theory that became a foundation of other theorists' work.

Classroom Application

The Ecological Systems Theory has been used to link psychological and educational theory to early educational curriculums and practice. At the center of the theory is the developing child, and all that occurs within and between the five ecological systems are done so to benefit the child in the classroom.

Critical Evaluation

Bronfenbrenner’s model quickly became very appealing and became accepted as a useful framework for psychologists, sociologists and teachers to study child development.

The Ecological Systems Theory provides a holistic approach which is inclusive of all the systems children and their family are involved in, accurately reflecting the dynamic nature of actual family relationships (Hayes & O’Toole, 2017).

Paat (2013) considers how Bronfenbrenner’s theory is useful when it comes to the development of immigrant children. They suggest that immigrant children’s experiences in the various ecological systems are likely to be shaped by their cultural differences. An understanding of these children’s ecology can aid in strengthening social work service delivery for these children.

A limitation of the Ecological Systems Theory is that there is limited research examining the mesosystems; mainly the interactions between neighborhoods and the family of the child (Leventhal & Brooks-Gunn, 2000). Therefore, it is unclear the extent to which these systems can shape child development.

Another limitation with Bronfenbrenner’s theory is that it is difficult to empirically test the theory. The studies investigating the ecological systems may establish an effect, but they cannot establish whether the systems are the direct cause of such effects.

Furthermore, this theory can lead to assumptions that those who do not have strong and positive ecological systems lack in development. Whilst this may be true in some cases, many people can still develop into well-rounded individuals without positive influences from their ecological systems.