by Pankaj Khadka
The Institute of Medicine has defined the ecological model, also known as the Socio-Ecological Model (SEM), as a model of health that emphasizes the associations and relationships among multiple factors affecting health. McLeroy et al. further defined the social ecological model as an avenue for health promotion to showcase the interrelated systems at five levels — intrapersonal, interpersonal, organizational, community, and policy levels, which were illustrated as concentric circles (McLeroy et al., 2012) Basically, SEM encompasses all factors, from micro to the macro level, that affect the health of an individual and the population at large and was developed to understand the effects of social and physical environment on human development.
The figure below, the Ecological Approach, shows the ecological model and how the five levels it consists of are interrelated and what they each constitute.
Figure 1. Ecological Approach (McLeroy, Steckler, Bibeau and Glanz, 1988).
Urie Brofenbrenner developed the SEM as a conceptual model in 1979 in his Ecological Systems Theory to extend existing ideas about interrelation between individuals and their environments by applying the ecological framework in the process of human development (McLeroy et al., 2012).
The model, further developed in 1988 by McLeroy et al., in the Ecological Model of Health Behaviors, outlined five levels of influence to determine the factor that determines health status and behavior (Winch, 2012):
- Public Policy
The table below illustrates how the SEM can be used in terms of human development by illustrating the five levels all of the association and relationships one makes from birth to death.
Level of Influence
Gender, sexual orientation, racial identity
Individual characteristics that influences behavior: Knowledge, skills, beliefs, self-efficacy
Interpersonal processes and groups providing identity and support
Rules, regulation, policies, structures constraining or promoting behaviors
Social networks, businesses
Community norms and values (community regulations)
Local, state, federal and national
Policies and laws that regulate or support healthy practices/actions
The McLeroy SEM can be applied to many human behaviors, an example of which would be the healthy eating habits in Baltimore (Ruderman, 2013).
The intrapersonal factors that determine one’s eating habits include the knowledge about different foods, expertise in preparing or cooking meals and one’s self-control over eating habits and diet. For example, a person who can prepare healthy meals is more likely to cook at home than a person who doesn’t know how to and resorts to take-outs.
The interpersonal factors include eating practices followed in families and eating habits among friends and colleagues. A mother who pays attention to healthy eating habits is more likely to encourage her children and family to indulge in similar practices than one who chooses to take her children to fast food joints for burgers and fries.
The organizational factors include schools and churches and the food practices followed in such organizations. Schools focused on the well being of their students pay stricter attention to the meals and their nutrient value provided to their children, and so encourage healthy eating habits from an early age.
Community factors are the community’s approach on eating habits and food choices. For example, a low-income community is more likely to be indulged in high carb concentrated diet like breads, rice, tortillas, etc. all of which have starch that makes a person less hungry for longer periods, which in turn results in obesity, a common pattern observed in low-income communities across America.
Public Policy factors are governmental rules and regulations on production and labeling of foods and stances on certain practices. Many countries, especially in Europe, have tried to control the amount of GMO’s or genetically modified food production, and implemented laws against infusing hormones or antibiotics in animal rearing and meat production.
While most of the limitations that first appeared in the SEM have been resolved, the current ecological modelers face three major challenges (Solidoro et. al, 2015). The first challenge is meeting the expectations of the scientific community and the general society and providing reliable tools and critical interpretation of the results, and also ensuring the limitations and approximations in any model. The second limitation is the challenge of prohibiting false expectations, which could arise from a promise to deliver what cannot be achieved, or not setting unreal expectations. The third limitation is ensuring the model is open to interbreeding with other scientific fields (Solidoro et. al, 2015).
(1) Solidoro C, Bandelj V, Cossarini G, Libralato S, Canu DM 2009. Challenges for ecological modelling in a changing world: Global Changes, Sustainability and Ecosystem Based Management. Ecological Modelling 220: 2825– 2827.
Available from: http://www.researchgate.net/publication/234056183...
(2) Ecological Model. American College Health Association. [Internet]
(3) Ruderman, M. An introduction to The Ecological Model in Public Health. Baltimore (MD): Johns Hopkins Bloomberg School of Public Health. 2013 June.
(4) Wendel ML, McLeroy KR. Ecological Approaches. Oxford Bibliographies [Internet]. 2012. [Last updated 2012 Nov. 11]
(5) Winch, P. Ecological models and multilevel interventions. Baltimore (MD): Johns Hopkins Bloomberg School of Public Health. 2012.