Are You Genetically More Empathetic? (OXTR)

Most babies will start trying to comfort people in distress by the time they’re a year old—but where does this behavior come from? Why can we sometimes literally feel the pain of other people? [R, R]

Empathy is one of the most important foundational traits for social interactions and relationships. Without it, human beings could only ever act selfishly, uncaring about the suffering of other people. With it, we are motivated to work together and to support each other [R].

As it happens, empathy is one of humanity’s most valuable evolutionary assets as well. Empathy promotes altruism, the tendency to take actions that benefit others at personal cost. Altruism, in turn, promotes cooperative family groups and larger social structures like villages [R].

It’s fair to say that the human species wouldn’t be as successful as we are without our ability to cooperate.

Empathy is the ability, or perhaps instinct, to feel (and try to fix) the suffering of others. Without it, cooperative social groups are unlikely to succeed.

The Dictator Game

The Dictator Game is a very simple experiment involving two anonymous “players:” the Dictator and the Recipient. The Dictator is given a sum of either real or fictional currency and asked to allocate a certain amount (which may be zero) to the Recipient, who has no influence on the Dictator [R].

In theory, a Dictator with no or low empathy would give nothing to the Recipient, while a Dictator with high empathy would give half or more away [R].

In a study of 301 people, over 47% were generous (half or more) givers. These highly empathetic participants had the most active and efficient oxytocin receptors (OXTR); they were especially likely to have the ‘G’ allele at rs1042778 and the ‘T’ allele at rs2268494 [R].

Why is OXTR important?

We’ve known for decades that oxytocin, sometimes called the love hormone, is vital for social bonding and empathy. That may be why the oxytocin receptor gene, OXTR, is among the best-studied genes in the human genome [R].

OXTR rs53576 is the best-studied SNP in this gene, but many more are likely to influence the efficiency of your oxytocin receptors.

Emotional Empathy

These days, it’s generally accepted that oxytocin increases emotional empathy. The more oxytocin we have and the more active our oxytocin receptors are, the more likely we are to feel the pain of others and to respond with altruism and generosity [R, R].

In genetic terms, the more active your OXTR and CD38 genes are, the more empathy you’re likely to feel [R, R].

Why is CD38 Important?

In recent years, this gene was identified as part of the pathway that releases oxytocin in the brain. More CD38 activity releases more oxytocin and enhances empathy and social communication [R, R].

OXTR (the oxytocin receptor) and CD38 (an oxytocin-releasing protein) may be the most important genes promoting generous giving and emotional empathy.

OXTR rs53576 [R]

• ‘G’ = More empathy and trust, more optimism
• ‘A’ = Less empathy and trust, more pessimism

OXTR rs2268494 [R]

• ‘T’ = More empathy in relationships, better communication with a partner
• ‘A’ = Less empathy in relationships, poorer communication with a partner

OXTR rs2254298 [R]

• ‘AG’ = The most empathy
• ‘AA’ = Less empathy
• ‘GG’ = Least empathy, less supportive of romantic partner

OXTR rs1042778 [R]

• ‘G’ = More empathy in relationships, more generosity, more total oxytocin in the body
• ‘T’ = Less empathy in relationships, less generosity

OXTR rs237887 [R, R]

• ‘G’ = More empathy, lower risk of autism
• ‘A’ = Less empathy, higher risk of autism

OXTR rs2268491 [R, R]

• ‘C’ = Less empathy, higher risk of autism
• ‘T’ = More empathy, lower risk of autism
• People with the 'CT' genotype showed the highest empathy in one study, followed by 'TT' and 'CC.' The difference between 'CT' and 'TT' may not be statistically significant [R].
• Another study found that the 'T' allele was linked with reduced rates of autism [R].

OXTR rs13316193 [R]

• ‘C’ = More empathy, lower risk of autism
• ‘T’ = Less empathy, higher risk of autism

CD38 rs3796863 [R]

• ‘T’ = More oxytocin released, more sensitive parenting
• ‘G’ = Less oxytocin released, poorer social communication

Autism and Empathy

Autism is a widely-defined developmental disorder that causes poor social communication skills, repetitive behavior, and fixation on special interests [R].

People with autism also don’t seem to experience empathy in the same way that neurotypical people do, and oxytocin may be behind the deficit [R, R, R].

One review of eight studies found four OXTR SNPs with significant links to autism: rs7632287 (‘A’ risk allele), rs237887 (‘A’ risk allele), rs2268491 (‘T’ risk allele), and rs2254298 (‘A’ risk allele) [R].

Other studies have found that a nasal oxytocin spray can reduce the severity of autistic behaviors and improve the social and emotional awareness of people with autism, though some respond much more strongly than others [R, R, R].

Rat Brains Without CD38

A recent study sought to confirm the role of oxytocin deficits in the development of autism. Researchers produced genetically modified rats without the CD38 gene, which codes for an oxytocin-releasing protein. Without CD38, the rats’ brains could not experience the effects of oxytocin because it couldn’t be released from neurons [R].

These CD38-negative rats developed signs and symptoms that are often used to model autism. They were much less flexible in their behavior and habits, unable to adapt to change without stress. They also had abnormal development in the prefrontal cortex, the part of the brain responsible for social interactions [R].

Autism is a developmental disorder marked by poor social communication skills and lower than average empathy. These deficits may be caused by a dysfunctional oxytocin system.