Kéri examined a gene involved in brain development called neuregulin 1, which previous studies have linked to a slightly increased risk of schizophrenia. Moreover, a single DNA letter mutation that affects how much of the neuregulin 1 protein is made in the brain has been linked to psychosis, poor memory and sensitivity to criticism. About 50 per cent of healthy Europeans have one copy of this mutation, while 15 per cent possess two copies
People with two copies of the neuregulin 1 mutation — about 12 per cent of the study participants — tended to score notably higher on these measures of creativity, compared with other volunteers with one or no copy of the mutation. Those with one copy were also judged to be more creative, on average, than volunteers without the mutation.
They hypothesize that people with this gene with high IQs are creative, while those with lower IQs are simply prone to the hallucinations that characterize the disease."