A study of twins suggests genetics may play a role in smoking, and in people’s ability to quit.
The study included 596 pairs of twins—363 identical, and 233 fraternal. Among identical twins, 65 percent of both twins quit in a two-year span if one twin quit. Among fraternal twins, the percentage was 55 percent. This indicates a genetic component is involved, since identical twins share the exact same DNA, while fraternal twins do not, Time reports.
The study looked at smoking behaviors of twins between 1960 and 1980, a period when the public’s perception of smoking changed in the United States. Researcher Fred Pampel of the University of Colorado noted in a news release that fewer people today smoke than in the past, but those who continue to smoke are more likely to be hard-core smokers who are most strongly influenced by genetic factors.
The researchers said current policies to reduce smoking, including bans on smoking in public spaces and high tobacco taxes, may not be as effective as they once were since many smokers today do not smoke out of choice, but rather because they are addicted to nicotine. More emphasis is needed on nicotine-replacement therapy and counseling, Pampel said.
The study appears in the journal Demography.