The Tweet: “Some rats are more compassionate than humans.”

A study into rat behaviour points towards empathy in the animal kingdom. We think of empathy – the ability to think compassionately about those around us – as a particularly advanced, human, trait. But rats in a lab experiment conducted by researchers at the University of Chicago learnt to free their trapped, distressed cagemates even though there was no benefit to themselves.

Empathy, referred to as ‘pro-social behaviour‘ by behavioural biologists is seen as an indicator of high intelligence in the animal kingdom, more frequently associated with animals such as great apes, elephants and dolphins. This study is the first of its kind to show this behaviour in rats.

“There are a lot of ideas in the literature showing that empathy is not unique to humans, and it has been well demonstrated in apes, but in rodents it was not very clear,” says author of the paper, Jean Decety, professor of psychology and psychiatry at the University of Chicago.

In the study, one rat was allowed to run free while another was trapped in a clear plastic tube. The trapped rat could be freed if a door was opened by the free rat. Once the free rats had learnt how to open the restraints they immediately freed them, and they ignored empty restraints or restraints containing toy rats. The rats freed each other for no reward.

“They are very smart and figure out if they pitch their nose up, they can open the door,” says Decety. “It’s not easy and it doesn’t happen by chance. They try hard and circle around.”

Next, the researchers placed two restraints in the cage, one with a trapped rat and another with chocolate to see which the free rat would free first. About half of the time the free rats released the trapped rat first and shared the chocolate.

“They open both doors and share the chocolate,” says Decety. “That’s amazing. They could eat all of the chocolate, but they didn’t.”

Whether this sharing of the chocolate 50 per cent of the time makes rats more compassionate than humans is for you to decide. Certainly great apes, ourselves included, display the highest level of empathy in the animal kingdom. “We’re a social species,” says Decety. “It’s good for us to help, it makes us feel good, it’s connected with dopamine and that’s good for everybody.”

Image: Jean-Jacques Boujot/ Flickr

This post was first published on The Untweetable Truth (22/01/2014)