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There’s a Gene for That…Or Is There?

Denyse O'Leary

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A CNN headline reports, "Blame genetics for bad driving, study finds." "Genes for," however, are dangerous words in genetics.

Recently, we looked at evolutionary psychology, the attempt to explain current human behavior as being governed by natural selection acting on how hominoid/hominin/human groups lived hundreds of thousands of years ago, so that the behavior is now encoded in the genes and brains of survivors. For example, we were told recently that men may have better navigation skills than women because these skills assist them in finding extra mates.

Science-Fictions-square.gifCuriously, the suggestion that there might indeed be innate differences between the way men and women think derailed the career of Harvard president Larry Summers. Summers made the mistake of invoking only present day data as it relates to the choice of a career in science. The navigation researchers, by contrast, were canny enough to invoke Darwinian evolution in the unresearchable past. So they may well be safe, and published in a peer-reviewed journal.

In a naturalist society, it is safer to invoke Darwin than evidence, no matter what one claims.

Of course, present-day research, properly handled, can advance naturalist claims about the human mind. It can be reinterpreted through genetics in the present day (genes create neurons and the mind is just neurons).

The timing is right. The Human Genome Project spiked widespread awareness of genes. In recent years, many claim to have identified specific genes or groups of genes that govern human behavior of interest, much in the way a light switch controls a circuit.

Thus we have heard about not only a "bad driver" gene, but a fat gene, "friends" gene, generosity gene, happiness gene, infidelity gene, liberal gene, pedophilia gene, psychopath gene, religion gene, "smother mother" gene, suicide gene, and violent media consumption gene, for starters.

One researcher offers a model for a "religiosity" gene, warning that if such people reproduce, "the religiosity gene will eventually predominate despite a high rate of defection." And in 2011, the New York Times electrified the corpse of the "crime gene" — even while admitting the weakness of the idea: "Many people with the same genetic tendency for aggressiveness will never throw a punch, while others without it could be career criminals." So the thesis is true except when it is not? And this is science?

A related outcome is personalized genetics, where people get their genome mapped to learn more about themselves, 23andMe-style. But, quite apart from recent troubles with the FDA, one’s personal Gattaca will likely be in reality, when critically analyzed, an uninformative bust.

Why? Because, in the real world of careful analysis, scientists are just not finding the "genes" that the headline writers need. British geneticist Steve Jones points out that most human traits are influenced by so many genes that there is no likely systematic cause and effect:

We know of more than 50 different genes associated with height … That has not percolated into the public mind, as the Google search for "scientists find the gene for" shows. The three letter word for — the gene FOR something — is the most dangerous word in genetics.

And the craze is not harmless, he warns. After media buzz about a genetic component to attention deficit hyperactivity disorder (ADHD), one British paper asked "Are some children just born bad?", suggesting that "previous thinking was flawed and some children, through no fault of the parents, are simply bad seeds."

We are only beginning to learn about epigenetics, the system within our cells that governs whether, when, and how a gene will be expressed. It threatens to upend the nonsense, except for one thing: We just haven’t heard much about that compared to all these "genes for."

In any event, the 1000 Genomes Project has found about 15 million gene variants in humans, "more than half of which had never been observed before." And that’s not the only unexpected recent finding. More than one percent of Scottish men in the "Scotland’s DNA" project were determined to be direct descendants of the Saharan Berber and Tuareg tribes. Did any genetic determinist predict that?

Similarly, on the controversial subject of genetics and intelligence (the "genius gene"), scientists used to estimate that about half a dozen genes affected it, then later upped the number to two hundred genes. Another estimate is about a thousand. One psychologist explained, "We can’t find the effects of any individual genes that are large enough to seem worth worrying about."

In the end, genes offer no more reliable an escape from responsibility for our behavior than claims of hominid ancestry do. But we never stop trying, do we?

Photo source: John McNicholas/Flickr.

Editor’s Note: Here is the "Science Fictions" series (the human mind) to date at your fingertips (the human mind).