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 it is relevant to humans. Some behaviors that would seem analogous, include wrapping the baby in a blanket, feeding, responding to the crying, singing to the baby at night to assist with sleep.
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 they are consistent. When they identify SES adversity, it seems related to the caregiving system. If the caregiving system has the appropriate resources and is able to respond an individuals needs, then development will be less impacted by adverse events. Allostasis will respond appropriately.
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?
One of the key items that sticks out to me is that a community that has experiences adverse events for several generations can express these adverse events in similar ways (personal communication, Tom Boyce, December 2014). For instance, certain racial/ethnic groups have higher incidences of specific types of illnesses, such as diabetes or stroke based upon generations of racism or political warfare. The accumulation of generations of adverse events that impact an individual’s genes, can be impacted by the socioeconomic and geographic conditions that someone is born into, and this can have either a positive or negative impact on the individual.