Despite research with twins that suggests 50% of our intelligence is genetic, pinning down the responsible genes has proven to be quite a difficult task:
"Researchers led by Robert Plomin of the Institute of Psychiatry in London obtained intelligence scores for 7,000 seven-year-olds based on verbal and non-verbal reasoning tests.
They also took DNA samples from the children in the hope of identifying genetic differences between the high and low scorers.
The huge trawl identified 37 variants in six genes that appear to be play some role in differences in intelligence.
But the individual effects of these genes was barely detectable. Together they account for just one percent of the variation in intelligence between individuals."
Just in case James Watson is checking the article, no, the blackness gene wasn't found among them. Intelligence, which should come as no surprise to anyone who has attempted to define it objectively, is far more complicated than one or two traits:
"Intelligence is a function of the way the brain is put together, and at least half of our genome contributes in some way or another to brain function, which means that in order to build a human brain, you need thousands of genes to work together," New York University psychologist Gary Marcus told the publication.