It is believed that the success of humans as a species depends to a large extent on our ability to cooperate in groups. Much more so than any other ape (or mammal for that matter), people are able to work together and coordinate their actions to produce mutual benefits. But what do we base our decisions on when we know whatever we do will affect those around us?

New research involving Dr Lucas Molleman, an expert in decision making and human cooperation in the School of Economics at The University of Nottingham, suggests that successful cooperation in groups depends on how people gather information about their peers, and how they base their cooperative decisions on it. The broader implication of this research is that the type of information we use to make our decisions can affect our social decision making.

The research, conducted at the University of Groningen in The Netherlands, is published today, Monday February 16 2015, in the academic journal Proceedings of the National Academy of Sciences.

Cooperation is of interest to both the natural and social sciences. Biologists wonder how cooperation could have evolved by natural selection: it is puzzling how cooperation can be beneficial when it is possible to behave selfishly and take advantage of the cooperative efforts of your group. Psychologists and economists try to understand why many people are willing to sacrifice their own welfare to benefit their social environment.

Understanding the decision making process

Dr Molleman, from the Centre for Decision Research and Experimental Economics, said: "The question that our research tries to answer is: 'How do people make decisions when their actions can affect the welfare of others?' More specifically, we want to know how people determine their behaviour when they have to cooperate in groups."

In these situations, a beneficial outcome for the whole group can be achieved if everyone works together. Individually, however, people might be better off by making selfish choices. Because of the possibility of others taking a free ride, people pay close attention their fellow group mates when they make decisions. For instance, they cooperate if others also cooperate, but act selfishly when others do not cooperate.

Who is selfish and who isn't?

Two hundred participants were invited to a computer lab at the University of Groningen. They were asked to make decisions that affected their earnings. Groups were formed in which the participants could choose between a selfish option (increasing their own earnings) and an option that benefitted all members of their group. In between making their decisions, people could gather information about their fellow group members; about the choices of the majority and information about which option paid off best.

Dr Pieter Van Den Berg from the University of Groningen said: "From previous research we know that people differ quite strongly in what kind of information they are interested in: some people are 'majority-oriented' and tend to look at the behaviour of the majority in their group, whereas others are 'success-oriented' and try to find out what kind of behaviour pays off best. In this experiment we studied how these different types of people behave when they have to cooperate in groups."

Dr Molleman said: "It turns out that behaviour in groups of success-oriented people was much more selfish than groups of majority-oriented people. As a consequence, the people in the majority-oriented groups tended to earn more money in the experiment since they cooperated more.