Three separate teams of researchers have discovered the same set of genes that increase risk of addiction and lung cancer in smokers.  This is an exciting discovery.  When explained at the New York Times, the conclusion was:

“The genetic variations, which encode nicotine receptors on cells, could eventually help explain some of the mysteries of chain smoking, nicotine addiction and lung cancer that cannot be chalked up to environmental factors, brain biology and statistics, experts said. ”

Similarly, one researcher commenting on the finding suggested: “This is really telling us that the vulnerability to smoking and how much you smoke is clearly biologically based” (psychiatry professor Dr. Laura Bierut of Washington University in St. Louis, a genetics and smoking expert who did not take part in the studies).

However, what both of these sources do not comment on is the fact that more and more evidence suggests that biology AND the environment interact to create health, disease, dispositions.  Certain genetic variations may lead to riskier profiles, given a stressful environment, but in some cases, the same genes that are riskiest under threatening conditions can also be most protective under nurturing conditions.   Following this type of exciting discovery, in my view, what will be even more exciting is to understand the way(s) that the genes identified interact with both the physical and social environment to allow some people with those genes to avoid smoking all together, some to become addicted immediately, and some to fall in between.  To say that genes will explain the “mysteries of chain smoking, nicotine addiction and lung cancer that cannot be chalked up to environmental factors, brain biology and statistics” is to miss the most exciting part of the story– the interactions between all of these factors.