Critical: Does Social Injustice Alter Our Epigenome (for generations to come)?

A new subset of genetics—“epigenetics”—appeared on the horizon in the 1990s and has been getting a lot of attention lately because it suggests some fascinating and frightening things about how “lifestyles and environment can change the way our genes are expressed” over the course of our lifetime. It has even reintroduced the once discredited idea that “traits acquired during an organism’s lifetime could be passed on to future generations”, and several studies on plants and animals have already shown that such modified gene expression can be inherited. Unfortunately, other more problematic scientific theories—that activists and social scientists worked hard to debunk—are also being resurrected in the wake of epigenetic research, including genetic (or epigenetic) determinism”.

On one hand, research into epigenetics has the potential to strengthen social justice movements, especially environmental justice, by uncovering yet another way in which low-income communities of color are disadvantaged on a global scale. We already know that the so-called “Green Revolution” has wreaked havoc on women’s health, a fact which becomes even more ominous in light of epigenetic research showing that exposure to pesticides (in mice) has negative impacts on their offspring’s health for at least four more generations. This is not good news for migrant farm workers and their families in the United States or Yaqui girls in Mexico who are already unable to breastfeed due to pesticide exposure. Although epigenetic studies of human populations are just beginning, there is already some cutting edge research that supports these findings- for instance, Kaati, et al, analyzed a century of demographic information from Sweden, exposing that even temporary famine experienced by grandparents can affect the life expectancy of grandchildren.

On the other hand, in our neoliberal age that stresses “personal responsibility” it may be more likely that this research will be used to blame people rather than help them. In his appearance on the PBS show about epigenetics, Dr. Randy Jirtle, Director of the Epigenetics and Imprinting Laboratory at Duke University, says that people have a responsibility to consider their lifestyle choices in light of the impact it could have on their children. In a similar vein, Dr. Szyf, professor of pharmacology and therapeutics at the McGill University School of Medicine, explains the relevance of epigenetics for psychiatry as follows:

the environment early in life anticipates the kind of life the person is going to live, for example whether it is going to be a stressful life or a calm life…The mother can convey to the offspring the type of world they are going to live in; that changes DNA methylation in the brain, and now we know, also in peripheral cells… I think that social environment can be as toxic as the chemical environment, if not more so.”

This sounds frighteningly similar to twentieth-century psychiatric theories on the etiology of mental illness- for instance, the once popular belief that children developed schizophrenia because they had a “schizophrenogenic mother”. In fact, has already jumped at the opportunity to re-open the mother-blaming theory- the website uses epigenetics to assert that “Research findings suggest that a mother’s parenting style can affect the activity of a child’s genes”, leading to mental illness. As always, no mention of the father’s (or other guardian’s) parenting style here.

In their interview for PBS, Szyf and Meaney explain their research on rats: offspring put in cages with “attentive” females could deal with stress better later in life than those raised by more “neglecting” females. To prove this was an epigenetic response, Szyf and Meaney gave the rats a drug that undoes the effects of epigenetics, which miraculously made the neglected rats “normal” again. How is this a women’s issue? Well, to build on this research there is a “10-year study, now underway, that will look at children from both nurturing and neglected backgrounds”. Szyf predicts that as a result of this research scientists will be able to show how stressful childhoods lead to poor health in adulthood, including depression, anxiety, drug abuse, diabetes, heart disease, and obesity. In other words, being a “neglecting” mom can give your kid heart disease. Surprisingly (or not surprisingly) the show fails to explore the idea that other stresses in a child’s environment—such as aspects of social inequality—might have similar effects. Given that disadvantaged groups, such as low-income African American women, often have disproportionately high levels of these illnesses (depression, obesity, heart disease, diabetes), will epigenetics be used to investigate the links between stress and poverty, racism, and sexism, or to blame these women for their children’s poor health?

In the Psychological Bulletin, Lawrence Harper (Chair of the Human Development program at UC Davis) does argue that social injustice can alter epigenetic expression:

oppression, is another recurrent, if unpredictable, and often long-term event that also meets the criteria for a selective advantage for epigenetic transmission. In this case, the nature of an adaptive response is not so obvious, but some aspects of temperament would be likely candidates for consideration….To the extent that undue bravery in the face of a potential enemy could lead to anything from reduced access to resources to death, caution would be an adaptive trait” (p. 11).

In other words, disadvantaged individuals may pass on “advantageous” personality traits to their children, like timidity. That’s a troubling assertion. Moreover, Harper decides that women are most likely responsible for this: “because the egg provides the larger contribution to the developing zygote, any epigenetic modifications are most likely to be transmitted via the mother”.

Epigenetic research is still in its infancy and there are certainly many scientists—perhaps even the majority—who think that the above studies relating to humans are correlational at best. However, the potential implications of future epigenetic research are virtually endless. In all likelihood, the field will lead to significant advances in medicine, including therapies for cancer that “turn off” the expression of certain genes. Yet the seemingly endless human propensity for using science to support ideological agendas makes it imperative that academics outside of the “hard” sciences, and activists, are included in the discussions about epigenetic findings in the coming decades.