Encouraging people to judge each other’s morals can get them to cooperate better, research shows.

In a study in Scientific Reports, researchers found that people who had the opportunity to judge each other’s morality were more likely to cooperate and trust each other in a group than those who could not make such evaluations.

“People really care about their moral reputation. So just knowing that you could be criticized keeps cooperation going.”

“Generally, people think of moral judgments negatively,” says Robb Willer, a sociologist at Stanford University, “but they are a critical means for encouraging good behavior in society.”

Researchers also found that the groups who were allowed to make positive or negative judgments of each other were more trusting and generous toward each other.

In addition, the levels of cooperation in such groups were comparable with groups where monetary punishments promoted collaboration within the group, according to the study.”

A better sort of sanction?

The idea that moral judgments are fundamental to social order has been around since the late 19th century. But most existing research has looked at moral reasoning and judgments as an internal psychological process.

Few studies so far have examined how costless expressions of liking or disapproval can affect individual behavior in groups, and none of these studies investigated how moral judgments compare with monetary sanctions, which have been shown to lead to increased cooperation as well, Willer says.

As part of the study, Willer and other researchers recruited 54 four-person groups who were randomly put into four conditions: control, interpersonal moral judgments, and two variations of material sanctions.

Each study participant began with 20 monetary units and used a private computer terminal to anonymously interact with people in her or his assigned group. The interaction lasted about an hour and involved a set of exercises in which group members were encouraged to donate their money to a fund that would benefit the group. Participants could see whether someone in their group donated the money or not and they would then be able to either praise their moral actions or enact a monetary sanction, depending on their assigned condition.

The study’s results show that moral judgments appear to be superior to monetary sanctions in achieving cooperation in groups. Although both conditions resulted in a similar level of cooperation, the groups that used money to punish each other’s unwanted behaviors led to instances of recrimination, where group members who were punished monetarily retaliated against those who sanctioned them.

Groups that used moral judgments showed lower rates of retaliation and higher levels of generosity, trust, and trustworthiness compared to the material sanctions conditions.

“People really care about their moral reputation,” Willer says. “So just knowing that you could be criticized keeps cooperation going.”

The researchers also found that people were more likely to give their opinion of other group members than to enact costly monetary sanctions. People gave out monetary sanctions about 36 percent of the time while passing judgments at 74 percent.

But those judgments were largely positive. People praised each other’s actions about 60 percent of the time, while negative judgments happened 14 percent of the time, according to the study.

Cheap motivation

The study’s results provide an important contribution to the existing body of research on collective action, in which material sanctioning has emerged in the past decade as a prominent solution to achieve cooperation and harmony in groups, Willer says.

While the research focus on material sanctions has produced critical insights into the evolution of sanctioning systems, Willer and his research partners call for more studies on the power of moral judgment because it appears to be a more effective, low-cost way to promote cooperation in groups.

“These findings suggest that the motivation to see ourselves, and be seen by others, as moral actors can be every bit as motivating as the drive to maximize material profit,” Willer and other coauthors write in the report.

Sociology Professor Brent Simpson and graduate student Ashley Harrell of the University of South Carolina are coauthors of the study. The National Science Foundation funded the work.