Smart children more likely to live longer and stay disease free, study suggests
School swots who faced a ribbing from their classmates for being too brainy will have the last laugh, according to a new study which found high IQ in childhood is linked to a longer life.
Researchers at Edinburgh University, Oxford and University College London followed up more than 65,000 people who took part in The Scottish Mental Survey in 1947, aged 11 to find out if intelligence as a youngster had affected their life, and death.
They discovered that by the age of 79, having a high IQ lowered the risk of dying from heart disease, stroke, cancer, and respiratory diseases.
They was also a lower risk of dying from injuries, digestive diseases and dementia.
“I’m being optimistic about these results,” said Professor Ian Deary, of the University of Edinburgh, who led the research.
“I’m hoping it means that if we can find out what smart people do and copy them, then we have a chance of a slightly longer and healthier life.
“We don’t fully know yet why intelligence from childhood and longevity are related, and we are keeping an open mind.
“Lifestyles (eg not smoking), education, health literacy, less deprivation, and genetics might all play a part. We and other research teams are testing these ideas.”
The lower risk of death even remained when accounting for factors which could have influenced the results, such as age, sex, and socio-economic status. In fact deprivation, such as unemployment, overcrowding, and other adverse living conditions are thought to account for only about 30 per cent of the IQ-mortality correlation.
Every extra 15 points IQ points was associated with a 28 per cent reduced risk of death from respiratory disease, a 25 per cent reduced risk of death from coronary heart disease, and a 24 per cent lower risk of death from stroke.
It means that a person with an IQ of 115 was 28 per cent more likely to have avoided death from respiratory disease at age 76 than a person with an IQ of 100 (the average for the general population).
15 more IQ points also cut the chance of dying from bladder cancer by 19 per cent, lung cancer by 25 per cent and bowel cancer by 11 per cent.
The researchers said people with higher IQs are more likely to look after their health and are less likely to smoke. They also tend to do more exercise, wear their seatbelts and seek medical attention when ill.
Other evidence suggests that IQ may be an indicator of good genetics and the efficiency of the central nervous system. Recent research found that fast reaction time is also linked to lowered risk of early death and high IQ.
A previous study by the same researchers in 2015 on the same cohort found that a 15 point IQ advantage increased the chance of still being alive by 21 per cent.
Some experts believe that IQ should be used, alongside factors of family history to assess people’s risk of developing health problems and dying early.
Kings College recently found that average intelligence has risen by 20 IQ points since 1950. The average lifespan has also dramatically increased over the same period.
The research was published in the British Medical Journal (BMJ).