Shame and honour increase cooperation

Honour and shame work equally well in encouraging social cooperation, according to a new study by mathematicians at UBC and Germany’s Max Planck Institute for Evolutionary Biology.

Published today in Biology Letters, the study reported on the results of a series of experiments with 180 first-year UBC students.

The research team shows that the threat of shame and promise of honour each increased cooperation by as much as 50 per cent, providing insights into strategies for tackling global issues such as overfishing and climate change.

"Shame and honour might evoke images of The Scarlet Letter or The Three Musketeers, but as tactics to drive social cooperation, they are increasingly important in the digital age of YouTube, Facebook and Twitter, where acts of shame and honour are being shared and propagated with unprecedented speed," says lead author Jennifer Jacquet, a postdoctoral researcher with UBC Mathematics and the Fisheries Centre.

"The study confirms that a shame tactic can be effective, but rather surprisingly, we’ve also found that apparently honour has an equally strong effect on encouraging people to cooperate for the common good," says co-author Christoph Hauert, an assistant professor with UBC Mathematics and an expert on game theory.

Jacquet says shame and honour are increasingly used to affect policy and cultural change. For example, to deter tax evasion, many U.S. states recently implementing policies to post names of tax delinquents online. Large-scale conservation programs use honour to encourage corporate and public involvement, such as labels that signal to consumers that products are sustainable, including Vancouver’s Ocean Wise seafood program. The new study is part of a series to establish a scientific foundation that informs future strategies to encourage cooperation on global issues.

The study builds on previous experiments showing that cooperation can also be achieved if participants can establish and maintain a good reputation, says co-author Manfred Milinski, an evolutionary biologist from the Max Planck Institute.

"In contrast to previous studies, the real-life reputation of our participants was at stake," says co-author Arne Traulsen from the Max Planck Institute. "This could be a prerequisite for shame and honor to work in other contexts."

The 'Public Goods' Game

In groups of six, participants were each given $12. Over 12 rounds of the game, participants were asked to decide privately whether to contribute $1 to a public pool – the total of which would be doubled and equally distributed among all players regardless of whether they contributed or not.

At the end of the experiments, all participants got to keep the remainder of their $12, plus their share of the public pool. This generates a temptation to withhold contributions and "free-ride" on the contributions of others.

To test the impact of shame and honour, players were told that at the end of 10 rounds the two least – or most – generous players would be asked to reveal their identities in front of the other participants, while the other four players would remain anonymous. Participants were recruited from the same class at the beginning of the term to ensure that they would meet again.

The team found that reputational effects induced by shame and honour each led to 50 per cent more cooperation (approximately $33 in total contribution) compared to control experiments where all participants remained anonymous (approximately $22 in total contribution).