Introduction to the special section on pathways underlying the impact of economic inequality on children’s development

It has been estimated that over 200 million young children being reared in poverty in low and middle income countries (LAMI) are failing to reach their developmental potential (Grantham-McGregor et al., 2007). For developmental scientists, poverty is viewed as a form of social address which summarizes a host of co-varying bioecological and psychosocial developmental influences into a single term (Chen, Hetzner, & Brooks-Gunn, 2010; Whipple, Evans, Barry, & Maxwell, 2010). Such summarization can lead to the oversimplified conclusion that it is the social address (e.g., poverty) which directly results in children not fulfilling their developmental potential. In contrast, within a bio-ecological framework (Bronfenbrenner & Morris, 2006), it is the multiple proximal psychosocial and biological characteristics, nested under the social address label, which are the primary drivers (mediators) of development (Huston & Bentley, 2010; Wachs, 2015).

Identifying the pathways through which poverty-nested proximal characteristics are linked to development is a necessary step in the development of intervention strategies that can facilitate the cognitive, academic, and social-emotional competence of the millions of children from LAMI countries who are being reared in poverty (Wachs & Rahman, 2013). However, progress in identifying such pathways for children in LAMI countries has been hampered by the fact that the bulk of developmental science research on poverty-development links has been carried out in high-income Western countries (Bornstein et al., 2012; Chen et al., 2010), even though over 90% of the world’s children are reared in LAMI countries (Engle, Rao, & Petrovic, 2013).

The goal of this special section of the International Journal of Behavioral Development is to attempt to close the gap between knowledge and need by presenting evidence from LAMI countries documenting specific pathways from biological and psychosocial risk and protective factors to children’s development. Geographically, the studies in this special section were carried out in a variety of LAMI countries from Latin America, Africa, and Asia, cover a wide age range from infancy to school age, and include both associational and intervention studies.

The research by Rubio-Codina, Attanasio, & Grantham-McGregor (2016), carried out in Colombia, identifies maternal education, and home stimulation as protective mediators in the path from family poverty to a variety of child development outcomes, as well as illustrating a multi-stage pathway with home stimulation mediating the influence of maternal education. The mediating role of home stimulation (parent reading to their child and shared parent–child play activities) is also documented in the Knauer et al. (2016) article based on findings from two large-scale intervention studies carried out in Mexico. In a multi-country study, Lopez Boo (2016) documents the importance of area of residence as a mediator of the influence of family socio-economic status, along with caregiver education level and child nutrition.

Going beyond the family, the research done in Ethiopia by Woldehanna (2016) shows that whether or not a child attends preschool depends on family economic circumstances and if the child lives in a rural or an urban area. One important yet paradoxical implication of the Woldehanna findings is that while preschool attendance can facilitate child development, it can also increase poverty-linked developmental inequality if only certain groups of children are attending preschool. The multi-country article by Santibanez and Fagioli (2016) is based on a large sample of adolescents from both middle- and high-income countries. Results from this study document that while higher family economic status is related to better achievement in mathematics, this link is mediated by the extent and quality of the students’ exposure to mathematics in school.

The remaining two articles in this special section explore non-mediational approaches to understanding links between poverty and reduced developmental competence in LAMI countries. The article by Black et al. (2016) illustrates the role of moderational processes, documenting how the degree of association between family economic status and child physical growth or cognitive performance can be attenuated by higher maternal education and home stimulation levels. Based on a review of available evidence, Wachs, Cueto, and Yao (2016) document that children growing up in poverty in LAMI countries are more likely to encounter both multiple covarying developmental risks and fewer protective influences than children growing up in poverty in high-income countries. The consequences of such differential exposure is illustrated by evidence from a UNICEF survey based on 52 LAMI countries, showing that as exposure to cumulative risk factors increase and exposure to protective factors decrease young children’s development is increasingly compromised.

Besides defining specific pathways from poverty to children’s development in LAMI countries, the seven studies presented here also have implications for generating intervention strategies to promote the development of such children. Specifically, the findings of both Lopez Boo (2016) and Santibanez and Fagioli (2016), documenting that the nature and impact of mediators varies across different countries, illustrate the importance of tailoring intervention strategies to specific contextual conditions, rather than assuming that “one size fits all.” Similarly, the findings by Rubio-Codina et al. (2016) that different mediators are associated with specific domains of development, the findings by Black et al. (2016) on child age as a potential moderator, and the findings by Wachs et al. (2016) on the consequences of exposure to multiple cumulative risks by poor children from LAMI countries, emphasize the need for coordination or integration across intervention programs targeting different risks, different children or different outcome goals.