A stress-blocking drug can be used as a ‘compassion pill’ that increases empathy, the ability to feel another’s pain, a study has shown.
The research also provides the first evidence that stress can sap the caring instincts of humans, possibly helping to explain acts of cruelty committed in the heat of conflict.
Scientists found that stress undermined empathy both in laboratory mice and volunteer students taking part in experiments that involved friends or strangers immersing their hands in freezing cold water.
In both cases, treatment with the stress hormone blocking drug metyrapone reduced the effect and increased the ability to empathise.
Metyrapone is a pill commonly used to treat Cushing’s syndrome, a condition that causes the body to produce excess levels of the stress hormone cortisol.
A similar result was achieved in the human study using a popular video game to boost social interaction between the student volunteers.
Study leader Jeffrey Mogil, from McGill University in Canada, said: “We found what in some sense might be thought of as the ‘secret’ to empathy; that is, what prevents it from occurring more often between strangers.
“It is quite intriguing indeed that this phenomenon appears to be identical in mice and humans.
“First, it supports the notion that mice are capable of more complex social phenomena than is commonly believed. Second, it suggests that human social phenomena might actually be simpler than commonly believed, at least in terms of their organising principles.”
Treatment with metyrapone caused volunteer students to feel more empathy for people they viewed as strangers
Previous research by the same team has demonstrated that mice experience empathy – once thought to be a wholly human ability – but only when they are known to each other.
Two cage-mates given a painful experience will feel it more than when each of them undergoes the same experience alone.
In the new study, published in the journal Current Biology, mice were subjected to mild pain by injecting them with acetic acid.
As before, cage-mates – but not strangers – who suffered the same experience together showed a greater reaction than they did when injected alone.
When they were treated with metyrapone, the mice began showing the same level of empathy to strangers as they did to their cage-mates. This suggested it was the stress of being with a stranger that previously inhibited their empathy.
A similar response was seen in the undergraduate volunteers. When friends were paired together and told to hold their hands in iced water, they reported a greater sensation of pain than individuals on their own or two strangers undergoing the same experience.
Treatment with metyrapone caused students to feel more empathy for people they viewed as strangers.
After taking the pill, participants not only reported more pain but also displayed more pained expressions on their faces.
They also touched their hands more often when witnessing another person’s pain.
The scientists found that asking students to play the music video game Rock Band for just 15 minutes had as much effect on empathy as the drug.
“It turns out that even a shared experience that is as superficial as playing a video game together can move people from the ‘stranger zone’ to the ‘friend zone’ and generate meaningful levels of empathy,” said Mogil.
He added: “President Barack Obama has described an ‘empathy deficit’ that fuels misunderstanding, divisions and conflict.
“ This research identifies a reason for the empathy gap and answers the vital question of how do we create empathy between strangers.”