Both environmental and genetic factors are implicated in the onset of regular smoking among U.S. adults. We show that, on average, over one-third of the variance in regular smoking is due to additive genetic influences. However, we also show variation in heritability estimates for regular smoking for different birth cohorts. Specifically, we show that the genetic influences are significantly higher among those born between 1925 and 1935 and those born between 1951 and 1956, and are largely unimportant for those born in the early 1940s and those born in the mid-1960s. The minimum heritability corresponds with a birth cohort that was in its early twenties at the time of the 1964 Surgeon General’s report on the dangers of cigarette smoking. The increasing genetic influence among the earliest cohort supports the causal social trigger model, and the declining genetic influence for those born after the mid-1950s supports the causal social control model. We argue that the smoking behavior of the birth cohorts between 1935 and 1954 is best characterized by the noncausal social push perspective.
