According to one science observation
Young men who smoke have lower IQs, study finds
"Only dopes use dope," goes the memorable warning about drugs. Now a Tel Aviv University researcher cautions that the same goes for cigarettes.
A study led by Prof. Mark Weiser of Tel Aviv University's Department of Psychiatry and the Sheba Medical Center at Tel Hashomer Hospital has determined that young men who smoke are likely to have lower IQs than their non-smoking peers. Tracking 18- to 21-year-old men enlisted in the Israeli army in the largest ever study of its kind, he has been able to demonstrate an important connection between the number of cigarettes young males smoke and their IQ.
The average IQ for a non-smoker was about 101, while the smokers' average was more than seven IQ points lower at about 94, the study determined. The IQs of young men who smoked more than a pack a day were lower still, at about 90. An IQ score in a healthy population of such young men, with no mental disorders, falls within the range of 84 to 116.
https://www.sciencedaily.com/release...0401151746.htm