A moral gene?

[Jim__]

That's the question asked in the title to a short article in Scientific American. The article has a link to the full paper in PLoS ONE. An excerpt from the Scientific American article:

Picture yourself standing at branching train tracks with a unstoppable train barreling towards you. On one side, an evil villain has tied five people, while on the other, he has tied only one. You’ve got the switch in your hands which chooses which track the train goes down. Do you feel it’s morally acceptable to choose to kill the one instead of the five?

...

But the connection between SSRIs and morality got Abigail Marsh and her colleagues from Georgetown University and the National Institutes of Health thinking. They knew that natural variation in serotonin reuptake ability exists in the population because of alterations in the promoter for one of the serotonin transmitter genes. People with the long form of the promoter (L) have normal levels of reuptake, while those with a truncated version (S) have reduced serotonin reuptake, similar to taking an SSRI. The researchers wondered if this natural variation influenced moral decision making in the same way that treatment with an SSRI does.

So, they took 65 healthy volunteers and tested their genes to see what versions of the promotor they had. Overall, 22 had two copies of the long form of the gene (LL), 30 had one of each (SL), and 13 had two copies of the short form of the gene (SS). They then asked these individuals to rate the overall morality of a variety of scenarios, including ones like the one above where one person is unintentionally harmed to save five others.

The results were clear: although the three groups showed no differences when presented with morally neutral scenarios or those where harm is intentionally caused to an individual, there were significant differences between groups when it came to scenarios of foreseen harm. Those with the long form of the promoter were much more willing to approve of harming one person to protect five. They felt that doing so was the better moral choice:



Those with the short form of the gene, however, felt that harming the one was morally neutral.

I guess the answer depends on how you define morality. I think most people here agree that there is no objective standard of morality. If that's so, this gene doesn't affect whether or not we act morally, but what acts we perceive to be moral. So, my vote is no, this is not a moral gene.