Applying the social push mechanism to smoking suggests attention to changes in the composition of smoker populations. As large numbers of people (regardless of genetic makeup) begin smoking, there will be a tipping point in the distribution of smoking environments where entrée into smoking becomes a primarily social phenomenon; genetically vulnerable persons are no more likely to begin smoking than genetically resilient persons simply because of the predominant social popularity of smoking. In contrast, if social influences discourage rather than encourage smoking, then genetic influences increase in salience because quitting is physiologically harder for some people than for others. The environment does not cause genetic influences to become more important for smoking but does allow their importance to show.
