Researchers have discovered that smokers have lower IQ’s than non-smokers. In a study of 20,000 young adults, Israeli researchers found that, the heavier the smoker, the lower the IQ. At a pack or more a day, young adult smokers between 18 and 21 years old averaged 7 points lower than their non-smoking counter parts. Interestingly, brothers scored very differently relative to whether or not they smoked.

Dr. Mark Weisser, the gentleman who led the study, points out that it is unclear which came first, the chicken or the egg: is smoking effecting the IQ’s of the individuals who smoke OR is it the individual with the lower IQ who is drawn to smoking? “It’s very clear that people with low IQs are the ones who choose to smoke. It’s not just a matter of socioeconomic status – if they are poor or have less education,’ he said. He suggests that the study can be used to help prevent smoking in younger people by targeting education at those with lower IQ’s.