Results show, among other things, a particularly close relationship between the intelligence and the risk of dying from diseases of the heart, vessels and respiratory tract

In a normal distribution, approximately 68% of people have an average IQ between 85 and 115.

Edinburgh (UK) - The largest study of this type confirms the correlation between the height of the intelligence (IQ) in childhood and life expectancy. The better the results obtained in an intelligence test, the lower the risk of dying from cardiac disease, stroke or respiratory infections during life, Scottish researchers report. However, this effect is not due solely to the fact that smarter people smoke less and usually take care of jobs that are less harmful to health, they explain in the "British Medical Journal". Rather, genetic phenomena that are still unknown can play a role here, which positively influence both the intelligence and the life expectancy.

There are several hypotheses explaining the link between intelligence and mortality, writes the researchers around Ian Deary and Catherine Calvin of the University of Edinburgh. It is known that smart people are more health-conscious by smoking less, doing more sports and being better informed about health issues. There is a link with the IQ for the choice of profession, the quality of the food consumed and other living conditions, which could also influence disease risks. Even after at least some of these influencing factors were taken into account in the statistical evaluation of the new study, the original relationship remained - a reference to possible genetic causes.

The researchers evaluated data from all children who were born in Scotland in 1936 and who completed an intelligence test at the age of eleven. This 45-minute test evaluated verbal and non-verbal thinking, with a maximum score of 76 points. It involved 65,765 people, from whom data were used until their death or until the age of 79 years. The better the performance in the IQ test, the lower the overall rates - regardless of the cause of death. A 15-point test result reduced the risk of respiratory disease, coronary heart disease and stroke by 24 to 28 percent. The probability of a fatal injury, dementia or gastrointestinal disease decreased by 16 to 19 percent with the same performance.

There was a connection with cancer in particular for stomach and lung cancer, and to a lesser extent also for other types of cancer whose risk increases with the consumption of tobacco. Overall, the correlations between IQ and disease risk in women were slightly more pronounced than in men. This study also does not clearly show that there are genes that simultaneously provide a high IQ and increase the chance of a long life.