Genetic marker for intelligence identified by Trinity scientists

RESEARCHERS AT Trinity College Dublin have identified one of the first genetic indicators of intelligence.

People who carry the genetic variant within a gene called NOS1 recorded lower IQ scores than those who do not carry the variant.

The same test was also carried out among patients with schizophrenia and yielded the same result. It is hoped that the research will bring us closer to understanding the nature of intelligence and mental health disorders such as schizophrenia.

The research involved thousands of participants in Ireland and Germany with an average difference in verbal IQ of five points. Significant differences were also found in the working memory of those who carried the genetic variation and those who did not.

Scientists have long concluded that intelligence variation is heavily influenced by genetics and may account for half of the variation in our intelligence. Identical twins separated at birth are much more likely to have the same IQ than children who grow up in the same household but who are not biologically related.

Dr Gary Donohoe, a lecturer in clinical psychology at TCD, said the genetic variant they have discovered is significant because it has been so difficult to make the connection between an individual’s genetic make-up and their intelligence.

“Although the genetics of human intelligence has been more widely studied than any other human trait, pinning down the specific molecular variants has been slow, probably due to the complexity of IQ and the large number of variants involved,” he explained.

A total of 600 people in Ireland and 1,700 in Germany participated in the study. Funded by Science Foundation Ireland, the study involved researchers at TCD, the University of Cardiff and Munich.