A study led by Professor Mark Weiser University Department of Psychiatry, Tel Aviv and Sheba Medical Center at Tel Hashomer Hospital has established that young people who smoke may have lower IQs than their non-smoking. Track 18 to 21 years for men serving in the Israeli army in the largest study of its kind, has been able to demonstrate a relationship between the number of young men smoked cigarettes and IQ.
The average IQ of a non-smoker was around 101, while half of smokers was more than seven IQ points less than about 94, the study found. The IQ of young men who smoked more than one pack per day were even lower, at 90. An IQ score in a healthy population of these young people without mental disorders, is in the range of 84 to 116.