Both warriors and worriers are needed in every society

Monday, August 9th, 2021

The gene that has been most studied for its involvement in pain modulation, David Epstein explains (in The Sports Gene), is the COMT gene, which is involved in the metabolism of neurotransmitters in the brain, including dopamine:

Two common versions of COMT are known as “Val” and “Met,” based on whether a specific part of the gene’s DNA sequence codes for the amino acid valine or methionine.

[...]

In both mice and humans, the Met version is less effective at clearing dopamine, which leaves higher levels in the frontal cortex. Cognitive testing and brain imaging studies have found that subjects with two Met versions — both animals and humans — tend to do better on and require less metabolic effort for cognitive and memory tasks, but that they are also more prone to anxiety and more sensitive to pain.

(Anxiety, or “catastrophizing,” is a strong predictor of an individual’s pain sensitivity.)

Conversely, Val/Val carriers seem to do slightly worse on cognitive tests that require rapid mental flexibility, but may be more resilient to stress and pain.

(They also get a better boost from Ritalin, which increases dopamine in the frontal cortex.)

[...]

David Goldman, chief of the Laboratory of Neurogenetics at the NIH’s National Institute on Alcohol Abuse and Alcoholism, coined the phrase “warrior/worrier gene” to describe the apparent tradeoffs of the two COMT variants.

[...]

In the United States, Goldman says, 16 percent of people are Met/Met; 48 percent are Met/Val; and 36 percent are Val/Val, leading him to suggest that both warriors and worriers are needed in every society, so there is widespread preservation of both forms of the gene.

I didn’t remember this passage from my original reading of the hardback edition back in 2013 — because it wasn’t in there:

So, I’ve included a relevant passage that didn’t make it past the first draft of this book.

It is about the BDNF gene, which codes for its namesake protein: brain-derived neurotrophic factor. The gene comes in two common varieties, known as “val” and “met,” and a National Institute of Mental Health study found that individuals with the met version performed more poorly on tests that asked them to recall scenes they had been shown. Follow up studies suggest that BDNF may also impact the kind of “muscle memory” involved in sport skill acquisition:

Comments

  1. Gwern says:

    That passage was better left out. Pretty much everything to do with COMT doesn’t replicate; it’s the poster-child of the candidate-gene debacle.

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