Human empathy is not only shaped by a person's upbringing and experience but also by their genes, scientists including one of Indian origin have found.
Empathy has two parts: the ability to recognise another person's thoughts and feelings, and the ability to respond with an appropriate emotion to someone else's thoughts and feelings.
The first part is called 'cognitive empathy' and the second part 'affective empathy'.
Fifteen years ago, scientists at the University of Cambridge in the UK developed the Empathy Quotient (EQ), a brief self-report measure of empathy. The EQ measures both parts of empathy.
Previous research showed that some of us are more empathetic than others, and that on average, women are slightly more empathetic than men.
It also showed that, on average, autistic people score lower on the EQ, and that this was because they struggle with cognitive empathy, even though their affective empathy may be intact.
Researchers from Cambridge and genetics company 23andMe conducted the largest genetic study of empathy using information from more than 46,000 participants, who completed the EQ online and provided a saliva sample for genetic analysis.
The study, published in the journal Translational Psychiatry, found that how empathetic we are is partly due to genetics.
About a tenth of this variation is due to genetic factors.
This confirms previous research examining empathy in identical versus non-identical twins.
The study also confirmed that women are on average more empathetic than men.
However, this difference is not due to our DNA as there were no differences in the genes that contribute to empathy in men and women.
This implies that the sex difference in empathy is the result of other non-genetic biological factors, such as prenatal hormone influences, or non-biological factors such as socialisation, both of which also differ between the sexes.
Researchers also found that genetic variants associated with lower empathy are also associated with higher risk for autism.
"This is an important step towards understanding the small but important role that genetics plays in empathy. But keep in mind that only a tenth of individual differences in empathy in the population are due to genetics," said Varun Warrier PhD student at Cambridge.
"It will be equally important to understand the non-genetic factors that explain the other 90 per cent," he said.
"This new study demonstrates a role for genes in empathy, but we have not yet identified the specific genes that are involved," said Thomas Bourgeron, professor at Cambridge.
"Our next step is to gather larger samples to replicate these findings, and to pin-point the precise biological pathways associated with individual differences in empathy," Bourgeron said.
"Finding that even a fraction of why we differ in empathy is due to genetic factors helps us understand people such as those with autism who struggle to imagine another person's thoughts and feelings," said Simon Baron-Cohen, professor at Cambridge.
"This can give rise to disability no less challenging than other kinds of disability, such as dyslexia or visual impairment," said Baron-Cohen.
"We as a society need to support those with disabilities, with novel teaching methods, work-arounds, or reasonable adjustments, to promote inclusion," he added.