By Emma Young

How do you persuade people to do the “right thing” when there’s a personal price to pay? What convinces someone to spend time and effort on a task like recycling batteries, for example — or literally spend cash by giving to people in desperate need?

It’s an important question. “Finding mechanisms to promote pro-social behaviour is fundamental for the wellbeing of our societies and is more urgent than ever in a time of key global challenges such as resource conservation, climate change and social inequalities,” write the authors of a new paper, published in Scientific Reports. Across a series of five online studies involving a total of more than 3,000 participants, Valerio Capraro at Middlesex University of London and colleagues provide evidence for a cheap, effective method: simply “nudging” people to reflect on what is the morally right thing to do. This simple intervention had some impressive effects, even increasing actual charitable donations by close to half.

The first study involved a simple test of altruistic behaviour. The researchers gave US-based participants 20 cents each and told them they were paired with someone else who had nothing. Right before being told that they could donate any part of that 20 cent pot to their (fictional) partner, one group was asked, “What do you personally think is the morally right thing to do in this situation?” Another was asked, “What do you think your society considers to be the morally right thing to do in this situation?” The third was simply asked how much they wanted to donate. This group donated, on average, 21.2% of their money, while members of both the ‘moral nudge’ groups donated an average of 30.6%. (Statistically, both nudges were equally effective.)

In further studies, the team found that the effect of giving moral nudges in this altruism task also “spilled over” to increase later cooperative behaviour, explored using an economic version of the classic prisoner’s dilemma game.

For the final study, 1,662 participants were given 50 cents and asked if they wanted to donate all or part to either Emergency, a humanitarian NGO that provides emergency medical treatment to victims of war, or Give for France, an organisation supporting victims of the July 14, 2016 Nice terrorist attack. (These experiments were conducted within a few days of this attack.) Morally-nudged participants gave 47% more to Give for France, and 39% more to Emergency, than those who hadn’t been given a moral prompt.

Strikingly, this combined average increase in actual charitable donations of 44% is very similar to the 47% increase observed when people who donated to a fund-raiser were entered into a lottery to win a cash prize. “Moral nudges produce…essentially the same increase but are free of cost,” Capraro and his colleagues note.

The researchers argue that their results could potentially influence policy aimed at increasing pro-social behaviour. However, as they also note, it’s early days for this research, and there are still questions. Would moral nudges increase pro-social behaviour in other spheres of life, beyond small-scale crowdsourced charitable giving? And what underpins the increase in pro-social behaviour: did the moral nudges work because participants sincerely wanted to do the morally right thing, or because they felt that such behaviour was appropriate in the context of these experiments?

The approach certainly seems promising. Now, the team writes, “future research should explore potential generalisations, with a particular focus to larger stakes, longer time spans and a greater number of interactions.”

– Increasing altruistic and cooperative behaviour with simple moral nudges

Emma Young (@EmmaELYoung) is Staff Writer at BPS Research Digest