The effect of Socioeconomic status (SES) deprivation on child development

 

What is SES deprivation?

Dimensional Model of Adversity and Psychopathology (DMAP), one of the recent models that study how dimensions of adversity experiences influence developmental processes and outcomes, defines deprivation as the absence of expected social or cognitive stimulation (1). The Index of Multiple Deprivation (IMD) is the official measure of relative deprivation in England. IMD follows an established methodological framework and defines relative deprivation by encompassing a wide range of an individual’s living conditions. People, for example, if they lack the financial resources to meet their needs, are considered to be living in poverty. However, if they lack all resources, not just income, they are regarded as deprived (2).

The UK’s ministry of housing, communities & local government examines seven distinct domains of deprivation to measure the level of deprivation in neighbourhoods (figure 1)(2):

1. Income
2. Employment
3. Health Deprivation and Disability
4. Education, Skills and Training
5. Crime
6. Barriers to Housing and Services
7. Living Environment

How does SES deprivation affect child development?

There is a well-documented association between early-life adversity (ELA) and a host of adverse outcomes for children. For example, children exposed to ELA show an increased risk of poor cognitive, socioemotional and physical health outcomes. In addition, deprivation has a unique influence on brain development (1).

Children often suffer from disadvantages during their lives, from educational achievement to employment prospects, if they grow up in a more deprived area. Their physical and mental well-being is also affected. Inequalities exist despite the downward trend in recent years for children not ready for school and young people not in education, employment or training (NEET) (3).

Abel et al. (2016) examined children at school entry age (4/5 years old) for executive function (EF) to predict their school readiness and their academic competence at a later stage. Availability of learning materials in the home for infants/toddlers is essential for their cognitive development and influences their school readiness (4).  Both Abel et al. (2016) and Vogel et al. (2021) have shown in their studies that there was a strong association between early-life SES and EF abilities; higher deprivation led to poorer EF outcomes (1,4).

In addition, Abel et al. (2016) demonstrated in their study that low-SES may increase the risk of deprivation and threat in childhood. Deprivation and threat, which accounts for SES-related cognitive ability retardations, are highly related, but their experiences are distinct. A threat is exposure to threatening or harmful experiences or stimulation (4). Although there is limited knowledge of how deprivation and threat together and independently influence child development within the low-SES context, a few studies specifically examined dimensions of deprivation and threat in the context of early life poverty (1).

DMAP uses experimental and theoretical observations of neurodevelopment to assume that deprivation influences the development of the association cortex, which is the area associated with higher-order cognitive abilities. This conceptualisation of deprivation comes from neuroscience literature that suggests that synaptic trimming in the prefrontal cortex and social and cognitive stimulation levels are associated. Reduced levels of these stimulations result in decreased dendritic branching and reduced synaptic density on dendritic spines. Synaptic density and dendritic branching help the brain connect and communicate information; however, the brain may be preparing for less complexity in the environment with their reduction. Consequently, this adaptation may impact the development of higher-order cognitive abilities such as cognitive control and EF (1).

No shortage of literature shows the link between early life deprivation and increased risk of reduced executive function (EF) abilities. Nevertheless, the bulk of the study has focused on children in Romanian orphanages adopted internationally after spending varying times in the orphanage. In a study sample of 2.5- to 4-years-old-post-institutionalized children have been found to have significantly reduced EF abilities compared to their non-institutionalised counterparts. Similarly, studies that use the Family Stress and Family Investment models and the DMAP models consistently found an association between social and cognitive deprivations and cognitive outcomes. A significant amount of work shows the association of early life social and cognitive deprivation with increased risk for reduced EF abilities and related aspects of cognition throughout childhood (1).

How does SES deprivation contribute to child mortality?

Infant mortality is a sensitive indicator of the effect of social determinants of health. Therefore, deprivation, particularly the kind that leads to infant/child death, should be avoidable in a wealthy society (5).

In the UK, infant mortality, predominantly among families in more deprived areas, has risen over the last four years, probably due to increased child poverty. Out of 23 Western European countries, the UK ranked 22 in 2019 for under five years old child mortality (5).

One way to eliminated infant and child deaths is to assess its relationship with deprivation. For example, the National Child Mortality Database (NCMD) 2019 report shows that for each decile of deprivation, the mortality risk is approximately 10% higher on average, going from lowest to most deprived; that is double the rate of the least deprived. Therefore, 23% of child death is avoidable if the child mortality rate in the most deprived half of the population is reducing to equal to that of the least deprived half (5).

NCMD report believes deprivation has a causal effect on child mortality; the more significant the deprivation, the higher the mortality rate. Intervention can drastically reduce child mortality through social justice by avoiding those inequalities that are judged to be avoidable by reasonable means. In the words of Professor Sir Michael Marmot, UCL Institute of Health Equity, “In a rich society, deprivation should be avoidable – particularly of the kind that leads to deaths of infants and children”(5).

Conclusion

Early life poverty or low-SES increases the risk of a high level of deprivation in children and exposes them to stressful or threatening input. Consequently, deprivation negatively affects the executive function abilities of children as well as their socioemotional and physical growth. In addition, deprivation may lead to infant/child mortality, which is currently in an upward trend in England. In a wealthy society, to experience this level of deprivation that leads to child mortality is unacceptable. For that reason, avoidable deprivation should be reduced or eliminated by tackling inequality in socioeconomic status.

Figure 1: The seven domains of deprivation that create the Index of Multiple Deprivation (IMD2019). From <https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/835115/IoD2019_Statistical_Release.pdf>

 

References

(1) Vogel SC, Perry RE, Brandes-Aitken A, Braren S, Blair C. Deprivation and threat as developmental mediators in the relation between early life socioeconomic status and executive functioning outcomes in early childhood. Developmental cognitive neuroscience. 2021; 47 100907. Available from: doi: 10.1016/j.dcn.2020.100907 Available from: http://dx.doi.org/10.1016/j.dcn.2020.100907 .

(2) Ministry of Housing, Communities & Local Government. The English Indices of Deprivation 2019 (IoD2019) - Statistical Release. 2019.

(3) Public Health England. Research and analysis
Chapter 6: social determinants of health. Available from: https://www.gov.uk/government/publications/health-profile-for-england/chapter-6-social-determinants-of-health [Accessed 21 Jun 2021].

(4) Abel GA, Barclay ME, Payne RA. Adjusted indices of multiple deprivation to enable comparisons within and between constituent countries of the UK including an illustration using mortality rates. BMJ open. 2016; 6 (11): e012750. Available from: doi: 10.1136/bmjopen-2016-012750 Available from: http://dx.doi.org/10.1136/bmjopen-2016-012750 .

(5) David Odd, Sylvia Stoianova, Vicky Sleap, Tom Williams, Nick Cook, Louisa McGeehan, Alison Garnham, Stephanie Davern, Rachel Rimmer, Judith Gault, Jennifer J Kurinczuk, Ingrid Wolfe, Karen Luyt. Child Mortality and Social Deprivation National Child Mortality Database Programme Thematic Report. 2021.