Genetic study offers clues to how intelligence changes through life
In a collaborative study between Universities of Edinburgh, Aberdeen and Queensland, researchers and scientists have found that genes are a contributing factor to intelligence at all stages of life.
The study published in Nature had used DNA analysis taken from 1,940 unrelated people, with data from those who took intelligence tests when they were 11, and again when 65-79.
The study also revealed that intelligence is mostly influenced by the environment. More than half a million genetic markers were examined and genetic makeup only contributes to 24%. Professor Peter Visscher of the University of Queensland, said: “Unique data and new genome technologies combined with novel analysis methods allowed us to tackle questions that were not answerable before. The results also strongly suggest how important the environment is helping us to stay sharp as we age.”
This wealth of cognitive data can be attributed to Scottish children. In Scotland of June 1932 and 1947 nearly all the children aged 11 took an intelligence test. These children were traced and asked to do the same again 50-60 years later.
Professor Ian Deary of the University of Edinburgh’s Centre for Cognitive Ageing and Cognitive Epidemiology, said: “Until now, we have not had an estimate of how much genetic differences affect how intelligence changes across a lifetime. These new findings were possible because our research teams were able to combine a range of valuable resources. The results partly explain why some people’s brains age better than others..”
Unfortunately none of the contributing genes or environmental factors was identified in the study. It does go on to help us in understanding the influence intelligence has on our ability to problem-solve and possibly to an individual’s outcome in life. Nature versus nurture continues.