Dozens of studies in the past few years have linked single genes to whether a person is liberal or conservative, has a strong party affiliation or is likely to vote regularly. The discipline of “genopolitics” has grabbed headlines as a result, but is the claim that a few genes influence political views and actions legitimate?

We don’t think so. The kinds of studies that have produced many of the findings we question involve searching for connections between behavior and gene variants that occur frequently in the population. Most of the 20,000 to 25,000 human genes come in hundreds or thousands of common variations, which often consist of slight differences in a gene’s sequence of DNA code letters or in repeats of a particular segment. For the most part, scientists do not know what effect, if any, these common variants, known as polymorphisms, have on the functioning of the proteins they encode. Genes predict certain well-defined physiological diseases—such as hereditary breast cancer and the risk of developing Alzheimer’s disease—but when it comes to complex human behaviors such as voting, the link is tenuous at best.