Genetic Determinism: The Dorothy L. Sayers Approach

Is genetics really the one-way street it is popularised to be in the media? There is media speculation about a fat gene, a beer belly gene, a creative dance gene, an addiction gene for nicotine metabolism and cigarettes and heroin), and speculation about an obsessive compulsive disorder gene. Maybe we would reap more benefit from Sure Start if we were to collect genetic material alongside the other socioeconomic data. I admit that my thinking on this is muddy and I've no idea how we would guarantee that the participants' DNA weren't kept on a national database in breach of their civil liberties. But, the current negative evaluation of the Sure Start programme tells me that we have a lot to learn. Something in me strongly rejects genetic determinism yet I am drawn to the argument that it is the tandem effect of genetics and environment that can influence our behaviour, health and many other aspects of our lives. Maybe this is the Dorothy L. Sayers approach. Lord Peter Wimsey once recounted a case where a young man had grabbed a pistol from a wall and shot someone during horse-play. Yet, the man responsible for the murder was the man who had loaded the pistol and so engineered events that this horse-play would occur and the target would die. Sure Start would be an excellent opportunity to explore genetics and environment in tandem.

What would collecting this data tell us? Well, probably a mixture of things that your granny could have told you plus some stuff that she wouldn't believe "in a million years". It would tell us whether the pistol was loaded and illuminate the circumstances under which it would be fired to devastating effect. J.P. of Contingency Table has an interesting summary:

...want to live until a ripe old age? Have parents that live long. Think you're a friendly, peaceful guy 'cause your mom raised you right? Think again. Able to try drugs just a couple times and never good [sic] hooked because of your strong will? Nope.

J.P. further suggests that our genes:

determine a probability distribution for the rest of our lives. Without a certain allele, will you live to be a hundred? It's certainly possible, but less likely. Will you end up an alcoholic even without a strong a priori susceptibility? Also possible. But also less likely.

And of course, it's nearly impossible to observe these probability distributions directly, but only in conditional form -- imagine someone with genetic tendency for high IQ being born in a wealthy US family vs. a malnourished Nigerian one. We can only observe distributions conditioned on a number of social factors. But the elucidation of these distributions will be a major legacy of genomic technology.

There is a fascinating and deliberately provocative discussion topic over on Scienceblogs: Why genetic determinism is inevitable in a meritocracy. One of the commenters asks, "what exactly is wrong with those with 'better' genes doing better?". Doubtless, there are 'better' genes (familial forms of cancer etc. and various genetic diseases): but for the rest, isn't that judgment being made from the narrow perspective of current social conditions? That is one of the significant difficulties with discussing this topic, there is a strong and dangerous undertow of rebarbative social commentary of the sort highlighted by Emerson in his essay, Fate:

Look at the unpalatable conclusions of Knox, in his "Fragment of Races,"—a rash and unsatisfactory writer, but charged with pungent and unforgettable truths. "Nature respects race, and not hybrids." "Every race has its own habitat." "Detach a colony from the race, and it deteriorates to the crab." See the shades of the picture. The German and Irish millions, like the Negro, have a great deal of guano in their destiny. They are ferried over the Atlantic, and carted over America, to ditch and to drudge, to make corn cheap, and then to lie down prematurely to make a spot of green grass on the prairie.

I was reminded of this particularly unpleasant commentary when I was reading the excellent series of articles in the New York Times about diabetes in New York. There is a strong demographic trend that means that the poor, and people from Central America, are disproportionately those who are affected by diabetes (among other groups). There are many other examples of chronic illnesses that affect people only when they completely change their environment and behaviour; including their family support and their general status in society. There is a lot to learn about the interaction of genes and environment in vulnerability to chronic illnesses.

Pharmacogenomics is an expanding field. We are learning more and more about why drugs are effective for some populations but not others. Writing about behavioural genomics, Peter McGuffin and his colleagues predict that:

identifying genes involved in behavioral disorders will do much to improve public perception and tolerance of behavioral disorders.

It's an optimistic prediction. Sure Start is currently failing its evaluation not because it isn't making a difference, but because it isn't making a difference to the most disruptive and socially-expensive groups. Do Sure Start interventions help people with a significantly different genetic make-up? Is there a reasonable prospect of designing interventions that would (for instance) improve the physical health and social success of people without the so-called resilience gene under prevailing social and environmental conditions? Are there (currently unimagined) circumstances under which this genetic variation would be advantageous? Is our current state of genetic knowledge too poor for us to make any assumptions about genetic determinism or behavioural genomics? Dorothy L. Sayers would remind us that the gun may be loaded, but the situation has to be engineered before it destroys the life of the intended party.