Sanctions 'enforce co-operation'

Participants were asked to play a virtual investment game

Having a system of sanctions is an effective way of enforcing co-operation, a German study says.

A University of Erfurt team found people worked better in groups if they could punish people who did not pull their weight, the Science journal said.

Researchers said it may have implications for how the public could be encouraged to tackle climate change.

But psychologists said the method was negative and outdated and suggested offering rewards was more effective.

In a group you will always get a minority who do not work for the common good Kairen Cullen, of the University of London

Researchers wanted to understand more about the nature of human co-operation in a bid to see how best to tackle issues such as climate change that require people to act in the best interest of the group.

The team asked 84 students to participate in a virtual investment game where they were given money to put into projects or in private accounts with the aim of amassing the most money.

Two thirds of participants elected to go into a group where they could not punish players who did not work as part of a group.

The rest opted for groups where they could financially punish freeloaders.

At the end of the first round, they were given information about performance and offered the option of swapping groups.

After a few rounds many from the non-punishing group started swapping to the other, including those who did not work with the rest of group.

Researchers found once in the punishment group, people started to work more collectively.

When the game ended after 30 rounds, the non-punishing group was almost completely depopulated and the punishing group operated at a higher level of co-operation.

Punishment

They added there was not much actual punishment being applied during the later rounds of the game, as apparently the threat of punishment induced co-operative behaviour.

Report author Bettina Rockenbach said: "We present support for the idea that institutions with built-in sanctioning mechanisms can establish norms of co-operation and out-compete institutions lacking mechanisms for punishing freeloaders."

But Kairen Cullen, a group behaviour expert from the University of London, said the idea of negative psychology encouraging action was outdated.

"In a group you will always get a minority who do not work for the common good.

"But it is much more in vogue to encourage people by offering reward or positive incentives. Offering negatives may encourage change in the short-term, but it does not alter behaviour in the long-term."