Researchers have found that stress is the reason why we find it hard to empathise with someone we do not know, reports BBC News. In separate tests in mice and people, empathy towards strangers increased when stress hormones were blocked by a drug.
Previous studies have shown that the ability to feel or share someone else's pain is not something unique to humans. Mice can feel empathy too. But in both species, empathy is stronger between those that recognise each other and all but absent between those unfamiliar with each other.
In this study, researchers treated mice with a stress-blocking drug and watched their response when confronted with other mice in pain. They found that the mice became more empathetic and more compassionate to strangers, reacting in a way they would normally react to familiar mice. When the mice were put under stress, they showed less empathy towards other mice in pain.
Tests in undergraduate students using the same drug showed exactly the same effect, the study said. Dr Jeffrey Mogil, study author and neuroscientist from McGill University in Montreal, Canada, said his team's findings suggest that the stress system in the brain can have a "veto" on our empathy system. "Yet few people would realise that there is a stress response when you're in a room with a person you don't know," he added.
[link url="http://www.bbc.com/news/health-30831145"]Full BBC News report[/link]
[link url="http://www.cell.com/current-biology/abstract/S0960-9822(14)01489-4"]Current Biology abstract[/link]