Are non-smokers smarter?

People who smoke are less brainy than those who do not. This was the conclusion reached by a team of Israeli researchers who studied over 20,000 military recruits, and found that non-smokers scored significantly higher in IQ tests.

All participants were aged 18. The average IQ for non-smokers was 101, while it was 94 for those who had started smoking before they joined the army. The more people smoked, the more likely they were to have a lower IQ.

The researchers also looked at 70 pairs of brothers within the army, where one brother smoked and the other did not; they found again that the non-smoking siblings were the smartest.

The findings do that indicate that smoking makes people less intelligent, the researchers said – rather, they suggest that people of a lower IQ are more likely to smoke.

While previous studies have already reached the same conclusion many of these have focused on children, or included people with mental health problems, who are more likely to smoke.

One of the advantages of this new study – aside from the massive number of people it looked at – was that no people with major psychological issues were included; as a prerequisite for joining the army, recruits must be judged to be mentally healthy.

Angry anti-smoking lobbyists have argued that tobacco companies target people of a lower intelligence with adverts and packaging. Auckland University expert, Dr Marewa Glover, called the campaign “proof of a successful campaign by the tobacco industry to target those with lower IQs by using devices such as cartoons and free samples.”

“They already know that people with poorer cognitive functioning, and populations where that is concentrated, are going to be more vulnerable to marketing tactics that are not dependent upon literacy skills."

Around the world, governments continue to promote smoking cessation campaigns to fight an addiction that is costing health systems billions of pounds each year. The World Health Organisation reports that for every one in ten adult deaths worldwide, smoking is the cause.