how poverty gets under the skin a life course perspective

How does early life poverty affect infants and children's health?

In conclusion, early life poverty exposes infants and children to numerous environmental and social risk factors and can set them on a life trajectory of poorer health across the life span with increased risk of chronic diseases and mental illness.

How does early life poverty affect the HPA axis?

Early life poverty is associated with impaired regulation of the HPA axis, including disruptions to the circadian rhythm and negative feedback, which can result in chronically elevated glucocorticoid levels.

Is there a link between fuel poverty and wellbeing?

And we found a causal link between fuel poverty and poorer wellbeing, as well as an increased inflammatory biomarker called fibrinogen.

Do income interventions reduce poverty in rural and urban areas?

There was no effect on height or hemoglobin concentration in either rural or urban areas. This study suggests that the impact of income interventions designed to reduce poverty depends on the specific outcomes measured and may also differ for families living in rural versus urban areas ( Fernald & Hidrobo, 2011 ).

Abstract

There is a large epidemiological literature documenting inverse relations between socioeconomic status (SES) and morbidity as well as mortality. In this chapter we focus on biological mechanisms to explain how disadvantage gets under the skin.

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How does poverty affect development?

Most explanatory work on the underlying psychological processes of how poverty affects development has focused on parental investment and parenting practices, principally responsiveness . Our primary objective in this article was to describe a third, complementary pathway—chronic stress and coping—that may also prove helpful in understanding the developmental impacts of early childhood poverty throughout life. Disadvantaged children are more likely than their wealthier peers to confront a wide array of physical stressors (e.g., substandard housing, chaotic environments) and psychosocial stressors (e.g., family turmoil, separation from adult caregivers). As exposure to stressors accumulates, physiological response systems that are designed to handle relatively infrequent, acute environmental demands are overwhelmed. Chronic cumulative stressors also disrupt the self-regulatory processes that help children cope with external demands.

How does poverty poison the brain?

This overview examines the uses of this research for neuroanthropology, highlighting the impact of inequality and how experience becomes embodied. Nevertheless, a simplistic cause–effect approach and the reduction of the social to the biological often hamper this type of research. A critical approach to how poverty poisons the brain provides the basis for making the shift to a more robust neuroanthropological approach to poverty. Neuroanthropology can utilize social embodiment, the dynamics of stress, and the production of inequality to transform research on poverty and children, and to make policy recommendations, do applied research, and craft and test interventions to deal with the pernicious impact of poverty.

What is TCP in education?

Based on evidence that strong and nurturing relationships between children and caregivers can be improved through evidence-based interventions, the Tulsa Children’s Project (TCP) was designed as a highly integrated set of programs for parents, teachers, and administrators at three high-quality early childhood centers serving low-income children from 8 weeks to 5 years. Three groups of interventions were coordinated into an integrated model, including physical health promotion programs (nutrition, exercise, increased access to care), teacher and administrative professional development and curriculum support, and a parent workforce training and development program. To address the stress associated with poverty and a documented history of individual trauma and adversity, mental health and socioemotional development concepts and activities were featured in each of the components.

How does socioeconomic disadvantage affect adulthood?

Socioeconomic disadvantage experienced in early development predicts ill health in adulthood. However, the neurobiological pathways linking early disadvantage to adult health remain unclear. Lower parental education-a presumptive indicator of early socioeconomic disadvantage-predicts health-impairing adult behaviors, including tobacco and alcohol dependencies. These behaviors depend, in part, on the functionality of corticostriatal brain systems that 1) show developmental plasticity and early vulnerability, 2) process reward-related information, and 3) regulate impulsive decisions and actions. Hence, corticostriatal functionality in adulthood may covary directly with indicators of early socioeconomic disadvantage, particularly lower parental education. Here, we tested the covariation between parental education and corticostriatal activation and connectivity in 76 adults without confounding clinical syndromes. Corticostriatal activation and connectivity were assessed during the processing of stimuli signaling monetary gains (positive feedback [PF]) and losses (negative feedback). After accounting for participants' own education and other explanatory factors, lower parental education predicted reduced activation in anterior cingulate and dorsomedial prefrontal cortices during PF, along with reduced connectivity between these cortices and orbitofrontal and striatal areas implicated in reward processing and impulse regulation. In speculation, adult alterations in corticostriatal functionality may represent facets of a neurobiological endophenotype linked to socioeconomic conditions of early development.

What are the challenges of growing up in rural America?

Young children growing up in rural America today face a number of challenges. Their parents have less income than urban families and less access to higher education and other important resources. On the other hand , young children in rural families often have access to extended family, live in single-family homes, and experience less random violent crime than children who live in urban communities. This chapter reviews the literature on rural families with young children and presents data from a representative sample of rural children (Family Life Project; FLP) to describe the lives of these families and their children from birth into elementary school. Results from the FLP suggest that parenting is particularly important in rural America, and that good parenting is a key mediator of the relationship between poverty indicators and children’s development. For example, we find that father language during early childhood is important for the prediction of language and school achievement for rural children in this sample. Household chaos is negatively related to positive child outcomes in development, although this also seems to be mediated through parenting. Interestingly, African American and non-African American FLP children come into elementary school above the national average on language and achievement tests, but both groups begin to fall behind in later elementary school. Good instruction in school does appear to help all children in language and literacy, but it especially helps children who enter school with lower skills.

How does poverty affect aggression?

Growing up in poverty increases youth risk for developing aggressive behavior problems, which, in turn, are associated with a host of problematic outcomes, including school drop-out, substance use, mental health problems, and delinquency. In part, this may be due to exposure to adverse school contexts that create socialization influences supporting aggression. In the current study, 356 children from low-income families (58% White, 17% Latinx, 25% Black; 54% girls) were followed from preschool through seventh grade. Longitudinal data included measures of the school-level contexts experienced by study participants during their elementary and middle school years, including school levels of poverty (percentage of students receiving free or reduced-price lunch) and academic achievement (percentage of students scoring below the basic proficiency level on state achievement tests). Regression analyses suggested little impact of these school-level contexts on teacher or parent ratings of aggression in fifth grade, controlling for child baseline aggression and demographics. In contrast, school-level contexts had significant effects on child aggression in seventh grade with unique contributions by school-level achievement, controlling for child fifth grade aggression and elementary school contexts along with baseline covariates. These effects were robust across teacher and parent ratings. Findings are discussed in terms of understanding the school-based socialization of aggressive behavior and implications for educational policy and prevention programming.

What constitutes health?

Concepts of what constitutes health, and theories about how health is produced and optimized, are constantly evolving in response to myriad social and cultural expectations shaped by our contemporary worldview, scientific advances, improvements in health interventions, and the changing capacity of the health system. Stimulated originally by a series of studies demonstrating how growth during early life is related to chronic health conditions that emerge many decades later, new research is demonstrating how complex developmental processes integrate a range of biological, behavioral, social, and environmental influences that modify gene expression, modulate physiologic and behavioral function, and dynamically shape different pathways of health production. These empirical findings are highlighting the limitations of the more mechanistic biomedical and biopsychosocial models of health, which fail to offer comprehensive explanations about such phenomena as the developmental origins of health, how stress affects current and future health, and the consequences of dynamic interactions between individuals and their environments over time. The comfort and certainty of simple, linear, and deterministic causal pathways are giving way to the uncomfortable uncertainty of nonlinear causal clusters that are networked together into complex, multilevel, interactive, and relational systems. Informed by new theoretical perspectives emerging from such fields of study as developmental psychology, systems biology, epigenetics, the developmental origins of chronic disease, and evolutionary developmental biology, a coherent transdisciplinary framework is emerging which we call Life Course Health Development (LCHD) and which is presented in this chapter as a set of seven principles: (1) health development, (2) unfolding, (3) complexity, (4) timing, (5) plasticity, (6) thriving, and (7) harmony. LCHD offers a new perspective that will guide future scientific inquiry on health development and facilitate synthesis of medicine and public health that links treatment, prevention, and health promotion and catalyzes more integrated and networked strategies for designing, organizing, and implementing multilevel health interventions that transcend individual and population dichotomies. We hope that the LCHD framework presented here, coupled with our explanatory narrative, will encourage theory building and testing, inspire innovative transdisciplinary research, and mature the framework into a scientific model with descriptive, explanatory, and predictive utility. Furthermore, we hope that LCHD will shine a light on the conundrum of how little attributable risk is explained in many studies of chronic disease, how early experience conditions future biological response patterns, and how these early experiences play through complex, environmentally influenced, and developmentally plastic health development pathways.

How does poverty affect health?

For example, poverty can change exposure to many factors that can influence health outcomes including family stress, discrimination, violence, neighborhood crime, undernutrition or nutritional deficiencies, inadequate housing, green spaces, overcrowding, noise pollution, environmental contaminants and toxins, amongst others ( Currie and Goodman, 2010, Evans, 2016, Walker et al., 2011, Wheeler et al., 2019 ). As many of these variables are not directly measured in studies, it can be difficult to disentangle the influence of income or SES and other factors commonly associated with poverty. In addition, there are protective factors that may moderate the association between early life poverty and health and lead to resilience, in particular the presence of supportive caregivers or other adults in a child’s life ( Gartland et al., 2019, Hostinar and Miller, 2019, Li et al., 2007 ). Throughout this review we highlight potential factors that may mediate or moderate the association between childhood poverty and biological outcomes, as some of these factors may represent promising targets for interventions.

What is the importance of a life-course perspective?

The DOHaD framework emphasizes the importance of a life-course perspective by highlighting developmental trajectories that contribute to adult health and disease ( Sdona, Briana, & Malamitsi-Puchner, 2020 ). An additional consideration for understanding the influence of the early life environment, including poverty, is that the consequences may depend on the developmental stage at which exposure occurs ( Hambrick, Brawner, & Perry, 2019 ). In addition to infancy and early childhood, experiences occurring in the prenatal period and even preconception have been shown to have lasting associations with some aspects of mental and physical health ( Chapin et al., 2004, McMillen et al., 2008 ), and there are also preliminary hints that such effects may be transmitted to future generations ( Burton & Metcalfe, 2014 ). Dynamic systems theory suggests that the more rapidly moving a dynamic system is, the more influence a perturbation will have ( Thelen & Smith, 1998 ). Therefore, even if the exposure is short, if it occurs during a time when a key fundamental process is occurring in a biological system the implications may be severe. Evidence to date suggests that poverty experienced very early in life, from the prenatal period to the second year of life, may have a particularly strong influence on adult health ( Lockwood et al., 2018, Ziol-Guest et al., 2012 ).

What are the first five years of a child's life?

The first five years of a child’s life represent a foundational period of brain development characterized by a series of stages beginning with neurogenesis and progressing to neural migration, maturation, synaptogenesis, pruning, and myelin formation ( Kolb and Gibb, 2011, Thomas and Johnson, 2008 ). This rapid neuronal growth and connectivity in early life is shaped by our environments within the constraints of our genetics, rendering children’s brains vulnerable to multifaceted contexts like poverty ( Thomas & Johnson, 2008 ). Children raised in poverty have, on average, poorer neurocognitive outcomes, lower educational attainment, higher rates of behavioural problems, and increased risk of mental health problems when compared to wealthier peers ( Evans, 2016, Evans and Cassells, 2014, Farah et al., 2006, Hair et al., 2015, Noble et al., 2005, Yoshikawa et al., 2012 ). Studies have also shed light on the neurobiological mechanisms that may underlie these associations by investigating differences in brain development between those raised in poverty and those raised in higher resource settings. In this section, we review evidence that early life income or SES associates with structural and functional differences in the brain, as well as possible mediators and moderators of these associations.

Why are children in poverty more susceptible to infections?

There are a number of reasons that children raised in poverty may be more vulnerable to infections, such as poor living conditions, including household crowding and poor sanitation, increased time in group childcare, and lack of access to health care, especially in countries without universal health care ( Baker et al., 2008, Brady, 2005, Freeman et al., 2017 ). However, as detailed below, beyond conditions that increase exposure to microorganisms, early life poverty has been shown to be associated with biological and molecular changes in an individual’s immune system that may alter their ability to fight infections and their overall health and well-being. There are two main branches of the immune system that are responsible for coordinating the body’s defense against invading pathogens: the innate immune system and the adaptive immune system ( Hoebe, Janssen, & Beutler, 2004 ). The innate immune system forms the first line of defense against infections, is more evolutionary conserved, and rapidly responds to unspecific molecular patterns of pathogens. The adaptive immune system, on the other hand, is composed of highly specialized lymphocytes (B and T cells) that are vital for building immunological long-term memory against specific pathogens, but typically has a response delay of a few days. As reviewed below, studies investigating the relation between early life income or SES and immunity have primarily focused on innate immunity with few examining components of adaptive immunity.

Does poverty affect cognition?

Evidence also suggests that poverty-related differences in brain structure may have implications for behaviour and cognition. For example, in one study, the correlation between cortical thickness and cognition differed by SES during development and was only significant for children from a low SES background ( Leonard et al., 2019 ). Another study found that children raised in low income households performed worse on standardized tests and up to 20% of the gap in test scores could be explained by maturational lags in the frontal and temporal lobes ( Hair et al., 2015 ). Household income also positively associated with children’s performance on neurocognitive assessments, and this relationship was partially mediated by differences in cortical surface area ( Noble et al., 2015 ). The potential cognitive associations with poverty may not be confined to the household context alone, as children living in poorer, in comparison to those in wealthier, neighborhoods had lower cognitive functioning regardless of individual household SES ( Taylor, Cooper, Jackson, & Barch, 2020 ). Combined, the evidence suggests that early life poverty associates with both global and regional structural differences in the brain and that these structural associations may be related to behaviour, academic attainment and cognitive performance.

Does early life poverty affect brain function?

In addition to associating with brain structure, measures of early life poverty also associa te with indices of brain function, with evidence coming from studies using functional magnetic resonance imaging (fMRI) as well as electroencephalograms (EEGs) ( Johnson et al., 2016, Lipina, 2016, Pavlakis et al., 2015 ). For example, in a large population-based cohort of adolescents, family income and parental education positively associated with, while neighbourhood deprivation negatively associated with, resting state functional connectivity assessed using fMRI ( Modabbernia et al., 2020 ). SES-brain activation associations have also been found during the performance of cognitive tasks. For example, in school-aged children, family SES associated with errors in a stimulus response mapping task and activation in the prefrontal cortex in the context of learning using fMRI ( Sheridan, Sarsour, Jutte, D'Esposito, & Boyce, 2012 ), as well as electrophysiological activity in the prefrontal cortex during a target detection task using EEG ( Kishiyama, Boyce, Jimenez, Perry, & Knight, 2009 ). In addition, maternal education associated with neural processing, assessed using event related brain potentials, during a selective attention task in 4–8 year old children ( Stevens, Lauinger, & Neville, 2009 ). Similarly, childhood SES has also been found to associate with neural activation during reading tasks ( Noble, Wolmetz, Ochs, Farah, & McCandliss, 2006) and activation of the hippocampus during a declarative memory task ( Sheridan, How, Araujo, Schamberg, & Nelson, 2013 ). Finally, adults raised in low SES environments also exhibited greater amygdala activation in response to threatening faces ( Gianaros et al., 2008) and an inability to suppress amygdala activation in response to a stressor ( Kim et al., 2013 ), providing evidence that associations between early life SES and brain function might be long lasting, consistent with the DOHaD concept. Combined, these studies indicate that early life poverty associates with neural function in several brain regions that are involved in information processing, emotion regulation, and memory. Future studies investigating the relation between these changes in neuronal function and behavioural and mental health outcomes throughout the lifespan will help shed light on the implications of these findings. In addition, randomized studies investigating the impact of poverty reduction interventions, such as cash transfers ( Rojas et al., 2020 ), on brain development will be critical for determining the causal nature of the relationship between early life poverty and brain structure and function.

Why do African Americans have difficulty entering the middle class?

Recent research on inequality and poverty has shown that those born into low-income families, especially African Americans, still have difficulty entering the middle class, in part because of the disadvantages they experience living in more dangerous neighborhoods, going to inferior public schools, and persistent racial inequality.

What is a life course RG?

The Life Course RG is dedicated to advancing research on life course theory and assessing how it can contribute to reducing poverty. The research within this RG focuses on issues of toxic stress, neurodevelopment, and epigenetics. The following are a few relevant projects within this RG.