Our ability to read people's thoughts and emotions through their eyes is influenced by our DNA, new research suggests.
'This is the largest ever study of this test of cognitive empathy in the world,' said Varun Warrier at the University of Cambridge, who co-led the study. He added that it is also the first large-scale study to examine this ability against variation in the human genome.
Previous work by the Cambridge team showed that some people are better than others at interpreting the emotional state of another person, just by looking at their eyes. And that women on average scored higher on this than men. The researchers used a test for cognitive empathy - the 'Reading the Mind in the Eyes' Test, or Eyes Test that they developed some 20 years ago.
In this new study, the Cambridge team, working with the consumer genetics company 23andMe and an international group of scientists, gave the test to nearly 89,000 people of European ancestry. The vast majority of them were 23andMe customers.
They found that the ability to 'read the mind' is influenced by specific genetic variants on chromosome 3 in women, but not men. Chromosome 3 contains the LRRN1 gene, which is highly active in the striatum, an area of the brain thought to play a role in empathy.
'This is an important step forward for the field of social neuroscience and adds one more piece to the puzzle of what may cause variation in cognitive empathy,' said Warrier.
The team also found that these same genetic variants were more likely to be seen in people with anorexia. 'Our research suggests that a genetic contribution to higher cognitive empathy increases one's genetic risk for anorexia,' wrote the researchers.
The authors hope that further investigation may improve understanding of how certain psychiatric conditions may be connected on a genetic level.
Although the findings suggest a genetic influence on empathy, the scientists emphasise the importance of taking into account other social factors such as early upbringing and postnatal experience, which may also have a role.
The team is now exploring 'precisely what these genetic variants do in the brain to give rise to individual differences in cognitive empathy', according to Professor Simon Baron-Cohen at the University of Cambridge, one of the lead authors. 'This new study takes us one step closer in understanding such variation in the population.'
The work was published in Molecular Psychiatry.