Could Our Genes Make Moral Consensus on Certain Issues Impossible?

Probably. Let’s take the example of a familiar moral puzzle that I think comes close to the issues raised in our article, which is the issue of investigative trials of new drugs. A couple of new drugs have recently been developed that dramatically improve outcomes for patients with malignant melanoma, who have previously not had good treatment options. Physicians disagree vehemently about whether it’s ethical to conduct controlled clinical trials with these drugs. Because, of course, controlled trials result in some patients not getting the new drugs. Some people think this is unfortunate but ethical because the only way to know if the new drugs really work is to do the trials. And determining whether the drugs work will help more people in the long term. Others say that to assign an individual, dying patient to the “control” condition of such a trial, knowing he will be denied a drug that may prolong his survival, is unethical.

These kinds of disagreements go back centuries, at least to Thomas Aquinas. And even he could only go so far as to say that it may be acceptable to perform an action that results in some greater good if you can foresee that your action will harm someone. It turns out there is no logical formula or equation that can determine what the right answer is in these circumstances. Recent cognitive neuroscience research highlights why: It’s because moral decision-making isn’t just rational; it has a big emotional component. We often have to rely on our “gut” emotional responses to decide how to act.

We’ve known for a while that genetic variants like the 5-HTTLPR affect people’s emotional responses. Our paper suggests that these emotional responses affect people’s moral intuitions. So the answer to the question “could our genes make moral consensus on certain issues impossible” is probably yes. Our genes influence our emotional responses to moral dilemmas. This means that a decision that strikes one person as right will strike another person as wrong, and because moral reasoning is not purely rational, there may be no rational way to decide on a solution.

Abigail Marsh is a professor of psychology and the director of The Laboratory on Social & Affective Neuroscience at Georgetown University.

Category: Q&A


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