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Threat of Group Extinction Motivates

Charles Darwin believed that competition between groups cultivates cooperation. A recent study from a team of researchers from Rice University, Texas A & M and the University of East Anglia supports this theory.

Charles Darwin

Charles Darwin

The study states,

When groups compete for resources, some groups will be more successful than others, forcing out less successful groups. Group-level selection is the most extreme form of group competition, where the weaker group ceases to exist, becoming extinct. We implement group-level selection in a controlled laboratory experiment in order to study its impact on human cooperation.

The Public Goods Game

The Public Goods Game

The researchers conducted a controlled laboratory experiment based on the standard linear public goods game. The 168 participants in the study were graduate students who did not know one another and were randomly assigned to groups of four. All interactions were conducted anonymously over a computer network. The game consisted of two blocks of 10 periods.

Each period, each subject was given 50 monetary units. Each group member secretly determined how much money to put into the group account and how much to keep in their own account. The amount in the group account was multiplied by a set factor and the payoff was equally divided among members of the group.

The first treatment replicated the standard public goods game. At the end of each period, subjects learned how much was contributed by others into the group account. They were told nothing about the contributions of participants in the other groups.

During the second treatment, group competition was introduced. At the end of the 10 periods, each group was ranked in terms of earnings against the other groups in the experiment.

Professor Rick Wilson, Herbert S. Autrey Professor of Political Science and professor of statistics and psychology at Rice University, one of the study’s authors, says,

History seems to support the idea that a group working together can overcome another group and drive them to extinction. But it had not been clear whether this was due to groups cooperating when in competition or to pressure of extinction through selection.

Over time, people contribute less to the public good and favor their private investments. But when we introduce group extinction, we see a remarkably different result. At the outset, individuals contribute almost everything to the group account. The pressure of group extinction results in individuals cooperating within the group.

Extinction was introduced during the third treatment. The participants were told that at the end of the 10 periods their group earnings would be compared to the earnings of the other groups. The groups that fell to the bottom one-third, however, would be removed from the experiment and would be unable to participate in the second block of 10 periods.

Wilson adds,

We find that group-level extinction produces very high contributions to the provision of the public group, while group comparison alone or individual extinction fail to cause higher contributions. Our results provide stark evidence that group-level selection enhances within group-cooperation.