1. Weaver et al propose that among rats, maternal behavior towards newborn pups influences their cortisol response to stress via epigenetic mechanisms that change the expression of glucocorticoid receptor gene for the rest of the pup’s life. They argue that because epigenetic patterns are established at specific developmental periods, there is extreme time sensitivity to when the pup is exposed to particular maternal behaviors (licking and grooming, in this case), and maternal behavior before or after that sensitive period window is not as important. Do you think this mechanism is relevant in humans? If so, what behaviors are most analogous to “maternal licking and grooming”?
Yes, I do believe that this mechanism is relevant in humans. Children learn and develop behaviors based on their primary influences and these learned behaviors can be present in adulthood. An example of the sustainability of learned childhood behaviors is diet and lifestyle. Children with or at risk of obesity, who are raised in households where they consume fattening foods, will have a metabolism that was shaped by their family eating behaviors. These early eating behaviors will cause other physiological and mental issues for the child as they grow up. Early social and behavioral health can shape and create long lasting impacts for physiological health outcomes.
2. Gruenewald, in contrast, emphasize the cumulative effects of SES adversity on a multi-system allostatic load measure. Do you think that the Gruenewald findings are consistent, inconsistent, or unrelated to the Weaver findings? Explain.
I believe that the Gruenewald findings are consistent with the Weaver findings, however both focus on separate angles of the issue. Weaver's findings exhibit that changes can originate from positive behaviors such as licking and grooming, while the Gruenewald findings demonstrate that physiological changes can stem from negative factors such as SES and social barriers which can shape the way our bodies withstand any sort of pressure in the future. The Gruenewald findings are consistent in the sense that they can be applied to the life course, but particularly adversities experienced in childhood have a greater risk in contributing to future behaviors than anything else. The cumulative model suggests that socioeconomic status adversity on a multi-system allostatic load measure is imperative throughout one's lifetime, much of the adversity related to SES is experienced in one's childhood.
3. Hertzmann and Boyce argue that “it is not genes or environment, nor is it genes and environment, but rather it is gene-by-environment interactions that influence developmental trajectories.” To what extent do you think that GxE interactions can contribute to major disparities along racial/ethnic, socioeconomic, or geographic dimensions?
Based on my coursework in biology and public health, I agree with Hertzmann and Boyce as well, that the gene-by-environment interaction is likely more of an important factor in influencing developmental trajectories. An individual is born with certain physiological qualities and into an environment which will influence the way the individual lives their life in the future. The environment is essential in shaping people as they develop their personalities and lifestyles. An interaction between the environment and an individual's health status can be directly linked, especially in the example i presented earlier regarding the relationship between an individual's diet and obesity. Geographic accessibility to fresh grocery stores, affordability of fresh produce and food supplies, accessibility to recreational facilities and sports, neighborhood safety and violence, racial and ethnic disparities, are all major determinants of health that shape the health outcomes for individuals. Understanding the social implications of one's health status allows researchers to evaluate and design culturally tailored public health interventions to tackle these healthcare disparities.