Optimistic Genetics


For the first time, scientists have pinpointed a particular gene variation linked with optimism and self-esteem, a new study reports.

A Genuine Scientific Image of the OXTR gene's G/G allele.

Two different versions – alleles – of the oxytocin receptor gene (OXTR) exist: an allele with the nucleotide “A” (adenine) at a certain location, and an allele with “G” (guanine) at that same location. Previous studies had found that people with at least one “A” molecule at that location tended to have heightened sensitivity to stress, and worse social skills.

But as the journal Proceedings of the National Academy of Sciences (PNAS) reports, a team led by UCLA’s Shelley E. Taylor were able to correlate certain alleles of OXTR with specific psychological symptoms:

We report a link between the oxytocin receptor (OXTR) SNP rs53576 and psychological resources, such that carriers of the “A” allele have lower levels of optimism, mastery, and self-esteem, relative to G/G homozygotes. OXTR was also associated with depressive symptomatology.

In other words, people who have either two “A” nucleotides, or one “A” and one “G,” at that specific location have lower-than-normal levels of optimism and self-esteem, and much higher levels of depressive symptoms, than people with two “G” nucleotides at that location on the gene.

Meanwhile, people with two “G” nucleotides at a certain location on their OXTR gene are more likely to be able to buffer themselves against stress. This is the most precise correlation between nucleotide differences and psychological traits that’s ever been discovered. And while this correlation isn’t a determiner of behavior, it does look like it’ll turn out to be an accurate predictor.

To figure this out, Taylor’s team studied the DNA from the saliva of 326 volunteers, and examined this data along with questionnaires each subject had completed. The questionnaires measured subjective feelings like self-worth, confidence, and positivity. The subjects also completed a set of questionnaires used to diagnose depression.

As is usual when stories like this – that is, about genes linked with certain traits – hit the press, there’ll probably be a flurry of articles with titles like “The Happy Gene,” making vague claims that the “gene for optimism” has been isolated. And that’s not what this study is about, at all – it’s about a connection between certain versions of a gene and the availability of certain psychological resources:

Some people think genes are destiny, that if you have a specific gene, then you will have a particular outcome. That is definitely not the case. This gene is one factor that influences psychological resources and depression, but there is plenty of room for environmental factors as well. Even people with the “A” variant can overcome depression and manage stress.

In short, what these allele differences mainly predict is a person’s susceptibility to certain psychological disorders if they encounter certain types of stress – not the likelihood that they’ll actually develop a given disorder.

It also remains to be seen what role, exactly, the neurotransmitter oxytocin, and its receptors, play in managing psychological troubles. As I’ve mentioned before, it’s been shown to lower stress and increase generosity – and it’s also involved in timing birth, encouraging hunger, and… heightening racist feelings.

Still, studies like this continue to being us more accurate and precise methods of diagnosing mental disorders – and even discovering if a person might be at risk for them. It’s also more evidence that our minds, like our bodies, are not all created equal – each of them is a unique neurochemical environment with its own thresholds of responsiveness.

So, next time somebody’s getting on your nerves, just tell them, “You better hope my oxytocin receptor genes are G/G alleles.” Take it from me: they’ll know exactly what you mean, and will probably back off and offer an apology.

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