Socioeconomic status is a multidimensional statistic that is influenced by numerous factors including income, education, and employment status (Havranek et al., 2015). It influences one’s ability to engage in certain levels of critical resources such as healthcare, education, recreational activities, housing, and food. Furthermore, communities of lower socioeconomic status have less access to medical care and they are exposed to more stressors. It has even been found that early experiences of adversity associated with lower socioeconomic status can alter the pace of neurodevelopment during childhood and adolescence (Rakesh et al., 2023). However, the impact of socioeconomic status on neurological development has been debated. Though further research is needed, it is largely supported by current research that socioeconomic status delays development and changes usual developmental patterns.
Before delving into the studies that have yielded this conclusion, it is crucial to grasp the various conceptualizations of adversity and its correlation with low socioeconomic status. This understanding is essential because not all children from low socioeconomic backgrounds necessarily encounter adversity solely due to their economic circumstances. Adversity is defined as the cumulative risk that a child faces either due to threats to one’s integrity, deprivation of certain social and cognitive abilities, and environmental instability. The overall cumulative risk is influenced by the composite socioeconomic status, which is a product of educational attainment, income, and neighborhood disadvantage (Rakesh et al., 2023). However, the exact link between adversity and low socioeconomic status is not fully understood, but researchers agree that low socioeconomic status reliably predicts the presence of adversity (Williams et al., 2016).
Additionally, it is important to consider the current limitations in studies that strive to link low socioeconomic status and neurodevelopment. Many of the current theoretical models that link low socioeconomic status predominantly look at the link between low socioeconomic status and neurodevelopment based on evolutionary development models. These evolutionary development theories conclude that childhood adversity may accelerate maturation and hence accelerate neurological development; however, they are unclear about how childhood adversity may affect the adult brain itself (Frankenhuis and Gopnik, 2023). Based on these evolutionary development theories, several other hypotheses corroborating this link between childhood adversity and neurological development have been proposed. One such hypothesis is the Stress Acceleration Hypothesis (SAH) which states that adverse early-life experiences accelerate neurodevelopmental processes because children experience high stress situations earlier than their peers who do not face their circumstances. In essence, they are being forced to reach adult-like functioning earlier so that they can process the more complicated emotions that they are being exposed to (Callaghan and Tottenham, 2015). Another dimensional model known as the Dimensional Model of Adversity makes distinctions between different aspects of adversity and how each aspect may generate different timelines of development.
The ‘change of pace’ model suggests that changes in the rate of development occur in response to filling the gaps in parental caregiving. Hence, it is likely that acceleration of neurodevelopment may be likely to occur in the early stages of childhood like infancy, after which neurodevelopment may slow because individuals are exposed to violence and threats (Roubinov, Meaney, and Boyce, 2021). However, the majority of studies have been cross sectional thus far; hence, evaluating the validity of this time-dependent framework is difficult.
Analyzing a collection of studies that take into account the multiple approaches to understanding development patterns as influenced by low socioeconomic status suggest that individuals with low socioeconomic status have lower brain thickness and volume and slower rate of change at all ages: infancy, toddlerhood, childhood, and adolescence (Rakesh et al., 2023). This evaluation is more consistent with the hypothesis that low socioeconomic status delays neurological development. However, it does not contradict that low socioeconomic status can accelerate neurological development at certain stages, showing development trajectories are simply different for individuals of low socioeconomic status than those who are not.
Further research has indicated a shift toward understanding the milestones of development in addition to the overall timeline. For instance, children from a lower socioeconomic status show less activation of the lateral prefrontal cortex, which is associated with reward and motivation (Moriguchi and Shinohara 2019). Additionally, children from a lower socioeconomic status were more likely to demonstrate neurological abnormalities (Chin-Lun Hung et al., 2015). Furthermore, low socioeconomic statuses can lead to epigenetic changes that are associated with a higher likelihood of neuropsychiatric disorders in the children (Zucchi et al., 2013).
Given this research, it is clear that there is some link between low socioeconomic status and neurological development, though the link is not fully understood. Further longitudinal studies need to be carried out in addition to studies on the impacts of low socioeconomic status on specific parts of the brain.
About the Author
Misha Nair is a junior at Harvard College, studying Neuroscience with a secondary in South Asian Studies.
References:
Before delving into the studies that have yielded this conclusion, it is crucial to grasp the various conceptualizations of adversity and its correlation with low socioeconomic status. This understanding is essential because not all children from low socioeconomic backgrounds necessarily encounter adversity solely due to their economic circumstances. Adversity is defined as the cumulative risk that a child faces either due to threats to one’s integrity, deprivation of certain social and cognitive abilities, and environmental instability. The overall cumulative risk is influenced by the composite socioeconomic status, which is a product of educational attainment, income, and neighborhood disadvantage (Rakesh et al., 2023). However, the exact link between adversity and low socioeconomic status is not fully understood, but researchers agree that low socioeconomic status reliably predicts the presence of adversity (Williams et al., 2016).
Additionally, it is important to consider the current limitations in studies that strive to link low socioeconomic status and neurodevelopment. Many of the current theoretical models that link low socioeconomic status predominantly look at the link between low socioeconomic status and neurodevelopment based on evolutionary development models. These evolutionary development theories conclude that childhood adversity may accelerate maturation and hence accelerate neurological development; however, they are unclear about how childhood adversity may affect the adult brain itself (Frankenhuis and Gopnik, 2023). Based on these evolutionary development theories, several other hypotheses corroborating this link between childhood adversity and neurological development have been proposed. One such hypothesis is the Stress Acceleration Hypothesis (SAH) which states that adverse early-life experiences accelerate neurodevelopmental processes because children experience high stress situations earlier than their peers who do not face their circumstances. In essence, they are being forced to reach adult-like functioning earlier so that they can process the more complicated emotions that they are being exposed to (Callaghan and Tottenham, 2015). Another dimensional model known as the Dimensional Model of Adversity makes distinctions between different aspects of adversity and how each aspect may generate different timelines of development.
The ‘change of pace’ model suggests that changes in the rate of development occur in response to filling the gaps in parental caregiving. Hence, it is likely that acceleration of neurodevelopment may be likely to occur in the early stages of childhood like infancy, after which neurodevelopment may slow because individuals are exposed to violence and threats (Roubinov, Meaney, and Boyce, 2021). However, the majority of studies have been cross sectional thus far; hence, evaluating the validity of this time-dependent framework is difficult.
Analyzing a collection of studies that take into account the multiple approaches to understanding development patterns as influenced by low socioeconomic status suggest that individuals with low socioeconomic status have lower brain thickness and volume and slower rate of change at all ages: infancy, toddlerhood, childhood, and adolescence (Rakesh et al., 2023). This evaluation is more consistent with the hypothesis that low socioeconomic status delays neurological development. However, it does not contradict that low socioeconomic status can accelerate neurological development at certain stages, showing development trajectories are simply different for individuals of low socioeconomic status than those who are not.
Further research has indicated a shift toward understanding the milestones of development in addition to the overall timeline. For instance, children from a lower socioeconomic status show less activation of the lateral prefrontal cortex, which is associated with reward and motivation (Moriguchi and Shinohara 2019). Additionally, children from a lower socioeconomic status were more likely to demonstrate neurological abnormalities (Chin-Lun Hung et al., 2015). Furthermore, low socioeconomic statuses can lead to epigenetic changes that are associated with a higher likelihood of neuropsychiatric disorders in the children (Zucchi et al., 2013).
Given this research, it is clear that there is some link between low socioeconomic status and neurological development, though the link is not fully understood. Further longitudinal studies need to be carried out in addition to studies on the impacts of low socioeconomic status on specific parts of the brain.
About the Author
Misha Nair is a junior at Harvard College, studying Neuroscience with a secondary in South Asian Studies.
References:
- Callaghan, B. & Tottenham, N. (2015, December 11). The stress acceleration hypothesis: Effects of early-life adversity on emotion circuits and behavior. Current Opinion in Behavioral Sciences. https://www.sciencedirect.com/science/article/pii/S2352154615001588
- Chin-Lun Hung, G., Hahn, J., Alamiri, B., Buka, S. L., Goldstein, J. M., Laird, N., Nelson, C. A., Smoller, J. W., & Gilman, S. E. (2015). Socioeconomic disadvantage and neural development from infancy through early childhood. International Journal of Epidemiology, 44(6), 1889–1899. https://doi.org/10.1093/ije/dyv303
- Frankenhuis, W. E., & Gopnik, A. (2023). Early adversity and the development of explore–exploit tradeoffs. Trends in Cognitive Sciences, 27(7), 616–630. https://doi.org/10.1016/j.tics.2023.04.001
- Havranek, E. P., Mujahid, M. S., Barr, D. A., Blair, I. V., Cohen, M. S., Cruz-Flores, S., Davey-Smith, G., Dennison-Himmelfarb, C. R., Lauer, M. S., Lockwood, D. W., Rosal, M., & Yancy, C. W. (2015). Social determinants of risk and outcomes for cardiovascular disease. Circulation, 132(9), 873–898. https://doi.org/10.1161/cir.0000000000000228
- Moriguchi, Y., & Shinohara, I. (2019). Socioeconomic disparity in prefrontal development during early childhood. Scientific Reports, 9(1). https://doi.org/10.1038/s41598-019-39255-6
- Rakesh, D., Whittle, S., Sheridan, M. A., & McLaughlin, K. A. (2023). Childhood socioeconomic status and the pace of structural neurodevelopment: Accelerated, delayed, or simply different? Trends in Cognitive Sciences, 27(9), 833–851. https://doi.org/10.1016/j.tics.2023.03.011
- Roubinov, D., Meaney, M. J., & Boyce, W. T. (2021). Change of pace: How developmental tempo varies to accommodate failed provision of early needs. Neuroscience & Biobehavioral Reviews, 131, 120–134. https://doi.org/10.1016/j.neubiorev.2021.09.031
- Understanding associations between race, socioeconomic status, and Health: Patterns and prospects. (2020). The Social Medicine Reader, Volume II, Third Edition, 258–267. https://doi.org/10.1515/9781478004363-030
- Zucchi, F. C., Yao, Y., Ward, I. D., Ilnytskyy, Y., Olson, D. M., Benzies, K., Kovalchuk, I., Kovalchuk, O., & Metz, G. A. (2013). Maternal stress induces epigenetic signatures of psychiatric and neurological diseases in the offspring. PLoS ONE, 8(2). https://doi.org/10.1371/journal.pone.0056967
