Magical Epigenetics

Epigenetics may have great promise, but gene expression doesn’t cancel nature

Most people see themselves and others as a combination of nature and nurture. Geneticists express this in terms of of our phenotypic, or observable, traits being a combination of genotypic traits and life experience.

This nature/nurture interaction is naturally complex. Behavioural geneticists isolate one from the other using Twins Studies and Genome Wide Association Studies (GWASs). In this way, they try to determine where trait variation is a function of the environment and where it is a function of nature.

Scientists also know there is a difference between a person’s immutable genetic make-up and their non-immutable gene expression. In other words, some complex combined effects of multiple genes can be ‘switched on and off’ through experience before and after birth. Epigenetics is the study of this gene expression.

Some things we may have once thought were immutable may turn out not to be after all, but instead open to epigenetic therapies. Scientists are steadily acquiring ever greater understanding of what stimuli, such as ante-natal nutrition or social experience early in life, produce what effects in respect of gene expression. One day, they might be able to help people avoid bad outcomes which could not prevented through future social experience or medical treatment alone. Obvious possible applications include specific clinical interventions and wider public health policy. Presently, the market for epigenetic health therapies is predicted to grow exponentially.

Elsewhere, some social scientists are studying how a better knowledge of epigenetics might help us create better learning conditions in schools, for example. But a problem is emerging.

Some research literature is already suggesting that epigenetics spells the end for the dichotomy of nature and nurture.

For example, an earlier Troubling Nature article highlighted one scientist writing that;

“the false dichotomy of nature versus nurture” helped “spawn(ed) an entire field of behavioral psychology grounded in the notion that differences among humans could be explained by genetics, inheritance and other biological mechanisms”.

A Harvard Univeristy briefing note on epigenetics includes:

“the old idea that genes are ‘set in stone’ has been disproven. Nature v nurture is no longer a debate”.

Although the Harvard comment is carefully and quietly qualified below in the text, the thrust of both these assertions is that nothing is set at birth; that everything will be alterable by increasingly sophisticated epigenetic therapies. This is, however, more polemic than reason. It is fallacious to argue that a greater understanding of the complexity of nature/nurture interaction negates the existence of the former. And reason suggests that genetic variation leads to variation in the possible scope for future epigenetic therapies.

What seems to be happening is that some scholars are seeking to employ epigenetics to reduce nature and natural variation to an irrelevance in order to evade the difficult social and ethical questions raised by genetic variation in humans. There are at least two risks which extend from this:

First, it amounts to a denial of scientific method. At this stage, we know little about the relationship between a person’s genetic makeup and their gene expression. Our new knowledge of the latter certainly suggests some conditions in future might be therapisable in some way, but this will come through understanding the greater complexity of the interaction of nature and nurture; not by denying nature’s existence and effect.

Second, social scientists who are critical of the assumptions of behavioural geneticists, often for philosophical rather than scientific reasons, but who promote epigenetics in social policy might find themselves inadvertently introducing genetics to social policy by the back door. Some scholars will understandably support this trend, including many behavioural geneticists, but it seems unlikely to be the intention of all the social scientists involved.

Epigenetcs might well become a science close to all our lives; but it isn’t a big bag in which to place all genetics’ ethical dilemmas before hiding it under the stairs.