LET ME TRANSLATE

You have a gene. It’s called “cholinergic receptor nicotinic alpha 5 subunit,” or CHRNA5 for short. It does important things inside your body. Certain sections of it, for example, dictate how your brain processes nicotine. That’s true for everybody. You may, however, have variants in and near this gene that put you at risk: They make you more likely to become a heavy smoker; to develop lung cancer and develop it earlier; and to struggle more than other people to quit. This is all backed up by solid published scientific research. Most of it has circulated for a decade or more.

A few years ago, Alex Ramsey, an assistant professor of psychiatry at Washington University, began trying to translate this research into action. He wondered: What would happen if smokers learned whether they had the CHRNA5 variants-that is, whether the genetic cards were stacked against them? There was a chance they’d turn into defeatists and keep puffing away. On the other hand, Ramsey hypothesized, they might react by making a special effort to cut back or quit.

Ramsey and his team recruited 108 smokers for a study. Each smoker sent a saliva sample to 23andMe, the ancestry-focused genetic-testing service. When.