Tag Archives: environment

This interview with Dr. Gary Evans, Elizabeth Lee Vincent Professor in the College of Human Ecologywas written for the Jacobs Foundation's BOLD initiative.

Reprinted from the Blog on Learning & Development, May 15, 2017.

Meeri Kim: Much of your work focuses on how children’s environment affects their health and well-being — in particular, the ways in which childhood poverty can lead to negative developmental outcomes. What are the components of poverty that tend to hit kids the hardest?

Gary Evans

Gary Evans: Throughout my work, I’ve tried to make the point that one of the reasons why poverty is harmful for kids is the chronic stress they experience as a result. One of the things that is unique and unfortunately quite powerful about childhood poverty is this accumulation of stressors, both physical and psychosocial. Physical stressors include housing issues, noise, crowding, and pollution. But the kids also experience psychosocial stressors like crime, family turmoil, and residential instability.

“Parts of the brain may change in children who grow up in poverty, leading to less efficient control and regulation of some cognitive and emotional processes than their wealthier peers.”

MK: How does constant exposure to such stressors impact the developing brain?

GE: The physiological response systems that are designed to handle relatively infrequent environmental stressors become overwhelmed for disadvantaged children. There is good evidence that parts of the brain linked to executive control — involved in coordinating things and keeping everything organized — are sensitive to chronic stress. Structurally as well as functionally, these regions may change in children who grow up in poverty, leading to less efficient control and regulation of some cognitive and emotional processes than their wealthier peers.

At the same time, other parts of the brain tied to automated, quick responses to stress and emergencies like the amygdala become over-developed and over-activated. So you have this bad mix of heightened emotional responses coupled with less regulation and control.

MK: Recently, you published a study on the link between childhood poverty and adult psychological well-being. What did you find?

GE: I looked at the psychological well-being of 24-year-olds in relation to their family income when they were 9 years old, finding relationships with a number of mental health and cognitive outcomes. Childhood poverty is linked to deficits in adult memory, greater psychological/physiological distress, and higher levels of aggression.

Another research interest is how motivation and helplessness differ for those who grew up in an impoverished environment. We have given both children and adults age-appropriate tasks to persist on, and we see consistently less persistence from the disadvantaged. When challenged, they’re much more likely to give up. To me, that unfortunately fits our model — if you grow up with a lot of stressors, your environment sets you up for feeling like you don’t have a sense of mastery or self-efficacy. This is a dynamic, particularly for children, that we need to look more at.

“If you grow up with a lot of stressors, your environment sets you up for feeling like you don’t have a sense of mastery or self-efficacy.”

MK: Given your findings on poverty, what kinds of policy changes could help enhance these children’s lives? Universal basic income?

GE: Various experiments have shown that when you increase the income of families in poverty, you may get better health outcomes, better parenting, and reductions in various negative outcomes. I believe any policy approach has to increase income in a way that is predictable and reliable, coupled with more available and affordable services for these families.

“Because poverty includes a convergence of multiple risk factors and stressors, it really means multiple interventions are necessary.”

Because poverty includes a convergence of multiple risk factors and stressors, it really means multiple interventions are necessary. You can’t just provide housing or job training. You really have to look across the board. A classic example is taking people off of welfare and giving them a low-income job, which is usually right around the minimum wage. However, if there is little or no childcare, the program winds up not being nearly as effective as it ought to be. Good-quality free or heavily subsidized childcare coupled with employment or job training may work better.

DIV. 7 AWARD WINNERS

Early Career Outstanding Paper Award winner: Sarah R. Moore

A summary of Sarah R. Moore's research, “Neurobehavioral Foundation of Environmental Reactivity.”

By Sarah R. Moore

Sarah Moore, Ph.D. student in Human Development

Sarah R. Moore, Ph.D. student in Human Development

In this review article, I propose a framework for understanding the neurobiological processes that guide how individuals navigate and internalize environments. Previous work brought to attention the empirical evidence that some individuals with particular temperaments, physiological characteristics and, more recently, genetic polymorphisms, demonstrate heightened effects of social environments on development (Belsky & Pluess, 2009). My review article, published in Psychological Bulletin, steps beyond this question of whether individuals vary in responses to social environments, which is now well-established, to why individuals differ in their responses. In other words, I set out to address: What underlies this variation in sensitivity to experience, and how does it develop?

Since the publication of seminal work on gene-environment interactions (Caspi et al., 2002, 2003), gene-environment interaction has become quite common in investigations of individual differences in responsiveness to environmental factors. Collectively, the work suggests that particular genes encoding neurochemicals relate to the degree that social contexts have enduring consequences on developmental outcomes. What was missing in this area was an explanation as to how variation of these neurobiological systems shapes individual differences in the enduring consequences of environmental factors. The first part of my review article thus addresses the neurobiological functions of genes commonly implicated in gene-environment interaction studies of sensitivity. These functions bridge genetic variation affecting neural systems to actual differences in neuroplasticity processes to environmental inputs, explaining mechanistically why particular genotypes might be linked to larger effects of the environment on development.

Inherent to the notion of plasticity is the critical role of experience. Plasticity means that environments are interacting with biology in the development of traits. Despite this accepted view of development as plastic, and thus involving an ongoing interplay of biology and experience, there still exists a heavy emphasis on genetics, in and of itself, wherever one or more genes might be implicated. In the second part of my review, a developmental framework is proposed that accounts for the dynamic nature of the biological processes that are affected by genes. Simply put, if a genetic factor shapes plasticity to the environment, then the history of environmental effects on the biology of the brain is as important to understanding outcomes as the genetic susceptibility factor: Any long-term consequences of such a factor is intrinsically dependent on the surrounding environmental context.

Taken together, the importance of this article lies in its novel insights into the mechanisms that may account for individual variations in sensitivity at a point where the field is in need of such an analysis. For the increasing number of developmentalists turning to research on genetic and biological markers of sensitivity, this article serves to inform the biological role of the prominently studied genes in human development. It also highlights other biological systems relevant to how experiences are registered and internalized. The article advances the current literature's myopic focus on identifying genetic plasticity markers to understanding the plasticity processes at play. The plasticity of neurobiological systems directly accounts for who responds and adapts and to what in the environment. This is essential for understanding developmental change, and for identifying targetable mechanisms of risk. After all, changing genes is not an option.

Ultimately, this article is intended to jumpstart more in-depth research aimed at understanding the nuanced developmental trajectories of individuals with different susceptibilities and unique histories. Understanding how biological tendencies are modified by experience will pave the way for tailored interventions that target the specific needs of individuals and, ultimately, improve psychological and physical health outcomes. I will be continuing this work as a scholar at the Child and Family Research Institute at the University of British Columbia. In this next phase, I will investigate the epigenetic mediators bridging the interplay of genetic variation and experience to neurodevelopment.

References

Belsky, J., & Pluess, M. (2009). Beyond diathesis stress: Differential susceptibility to environmental influences. Psychological Bulletin, 135 (6), 885–908.

Caspi, A., McClay, J., Moffitt, T. E., Mill, J., Martin, J., Craig, I. W., et al. (2002). Role of genotype in the cycle of violence in maltreated children. Science, 297 (5582), 851–854.

Caspi, A., Sugden, K., Moffitt, T. E., Taylor, A., Craig, I. W., Harrington, H., et al. (2003). Influence of life stress on depression: Moderation by a polymorphism in the 5-HTT gene. Science, 301 (5631), 386–389.