Smoking is directly correlated with a lower IQ, according to a study conducted by researchers from Tel Aviv University in Israel and published in the journal Addiction.
Researchers tested the IQs of more than 20,000 healthy men between the ages of 18 and 21 who were either serving in the Israeli military or who had recently completed their service. Twenty-eight percent of the men in the sample smoked, while 3 percent were former smokers and 68 percent had never smoked.
The average IQ of the smokers was 94, compared with 101 among the non-smokers. Men who smoked more than a pack of cigarettes a day had an average IQ of 90. Although a normal IQ falls between 84 and 116, the difference observed in the study is still considered significant.
Source: Natural News, August 16, 2010