Behavior Genetics 1999; 29:5, 291-301.
Phenotypic and Genetic Factors in Motives for Smoking.
Gynther, L. M., Hewitt, J. K., Heath, A. C., & Eaves, L. J.
Underlying phenotypic and genetic factors involving motives for smoking were assessed using data from 1756 twins, including 390 complete pairs. Respondents were aged 50 or older and included both current and former smokers. It was found that genetic effects accounted for a significant amount of variance in the four hypothesized pharmacological motives for smoking (Sedative, Stimulative, Addictive, and Automatic), as did shared environment. One common effect explained the genetic variance; no genetic influence uniquely affected any specific motive. Therefore, individual differences in the hypothesized pharmacological motives for smoking appear to originate from a common genetic pathway.