Human Social Genomics

The DNA Spiral by Charles Jencks

 

Evolutionary theory has accustomed us to thinking of our genes as stable and essentially unchanging. Genetic change takes place over generations through mutations that give the bearer a competitive advantage in a specific environment. Genes are what we inherit from our parents and pass on to our children. But the emerging field of human social genomics looks at how environmental factors — low socio-economic status, stress, or pollution, for example — can influence our genes over the course of our lives. The good news is that our behaviour — making contact with other people or acting together to change our social environment, can have positive effects on our genes and our health, too.

In “Human Social Genomics,” an article published in PLOS Genetics in August 2014, Steven W. Cole of the UCLA School of Medicine summarizes the main findings in the field to date. The research is based on the observation that there is a difference between the gene blueprint we have and the genes that actually get expressed. Researchers noticed that gene expression in birds and insects could be influenced by environmental conditions. It was subsequently observed that in the case of humans a number of genes “showed significant differences in expression across pastoral, rural and urban social environments.” From there, more specific social contexts could be analyzed. More recently, researchers have addressed the impact of social adversity on our genes.

They have found, for example, that different kinds of stress or social adversity can bring about what is called a “conserved transcriptional response to adversity” (CTRA), which can result in the expression of inflammation-promoting genes while reducing expression of antiviral ones. The CTRA can be kicked off by various things — low socio-economic status, chronic stress, bereavement, post-traumatic stress disorder, cancer diagnosis, or other stressful events. What’s more, not only objective, but also subjective factors can influence gene expression. In the case of socially isolated individuals, for example, researchers found that people who had little contact with others were not affected in the same way as people who suffered from feelings of loneliness.

Human social genomics provides important insights into how social conditions can lead to various forms of ill-health. Its findings underscore the importance of urban planning, environmental regulation, reducing income inequalities, preventive healthcare. But our own behaviour can influence gene expression, too, as Cole explains:

Philosophers have long distinguished between a hedonic form of well-being generated by the pursuit of positive emotional experiences and consummatory self-gratification (i.e., self-focused happiness) and a more eudaimonic form of well-being that stems from devoting one’s efforts to a noble cause or purpose outside the self (i.e., self-transcendent happiness). Frederickson and colleagues found that high levels of eudaimonic well-being were associated with significantly lower levels of CTRA-related gene expression (i.e., a more favorable, or less threatened, molecular profile). In contrast, people who showed comparatively high levels of hedonic well-being relative to their level of eudaimonic well-being showed significantly elevated CTRA gene expression . . .

By participating in attempts to change the social environment, getting involved, we can do our genes a favour, it seems. When we reach out to other people and create social links, or when we try to change things for the good of all, our own health can improve too.

— Catherine Vigier, Zeteo Contributing Writer

 

References

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