Hopelessly devoted to good: it’s more than love that keeps us together
Study of altruism among newlyweds shows their bond goes beyond romance, and there's a good evolutionary reason for it
You want to stay in and watch TV, your partner wants to go out for a romantic Valentine’s date – and you acquiesce without a fight.
If this rings a bell with you, brain boffins have worked out what’s going on: you’re not sick, you’re just in love.
Altruism has long been a source of scientific interest, and a new study from the US looked inside newlyweds’ brains to see how activity correlated with selflessness directed at their romantic partners.
Reporting their findings in the journal Behavioral Neuroscience, the team said they discovered pathways in the brain that in other animals are linked with bonding.
Neuroscientists believe altruism evolved as a strategy for ensuring the survival of relatives so that some of your own genes are passed down through generations.
Bianca Acevedo, from the neuroscience research institute at the University of California Santa Barbara, said in humans this basic idea took on extra dimensions.
“It would make sense that people would be particularly invested in the wellbeing of their partners because they want to live long, happy, healthy lives together,” she said.
“And in the case of newlyweds, some of them will want to have children. So being selfless towards their partner is an investment in their offspring.”
Acevedo’s team tested each of their newlywed subjects for two genetic variants involving sensitivity to the hormones oxytocin and vasopressin.
Oxytocin is popularly known as the “cuddle hormone” and plays a key role in trust, empathy and bonding. Vasopressin has also been connected with pair bonding.
After evaluating their levels of romantic altruism and empathy, the scientists put the newlyweds into a functional magnetic resonance imaging machine to see how different parts of the brain activate in response to different types of stimuli.
The participants were then shown pictures of their romantic partners, friends and strangers with different facial expressions. The researchers explained what the person in the picture was feeling and why, in order to elicit an emotional response.
When participants felt a strong sense of empathy with the person in the picture, regions of the brain associated with emotion and emotional memory lit up. “It’s almost like the brain is responding in a way that signals: ‘This is important, pay attention’,” and Acevedo.
Individuals with genetic variations that made them more sensitive to oxytocin and vasopressin exhibited stronger emotional responses across the board.
The researchers also found that brain regions that activated specifically in response to a partner’s face were the same regions that are critical in other animals during studies of pair bonding and attachment.
This suggests that our brains have pathways devoted specifically to attachment-related behaviours. However, some of these attachment pathways showed activity even when participants saw strangers’ faces, providing evidence of the intricate notions of empathy and altruism at play in humans.
Acevedo is now studying how mind-body activities such as yoga influence how individuals respond to partners struggling with memory problems.
“It’s important that we’re thinking about these systems and these behaviours beyond romance,” she said. “When people think about relationships they tend to think of romantic love as being really important. But we’ve forgotten some of the other basic and important reasons that people are together, like to take care of each other.
“Beyond romantic love, we live long lives together. Many of us raise children together, or take care of each other into old age,” continued Acevedo. “And altruism is deeply rooted in our evolutionary, neural and genetic framework.”