Study: Uninformed group can help achieve consensus

While it is a commonly appreciated theory that more vocal and persuasive individuals can successfully win the vote of those who are either unsure of or uncommitted to an opinion, a Princeton research team suggests that an uninformed group of individuals actually tends to side with the numerical majority, thus helping to achieve a democratic outcome.

The team found that an uninformed group of individuals might be effective at counterbalancing an outspoken minority that might have had success winning over even informed members of the majority thereby restoring majority rule.

To test the theory, the researchers first created mathematical models based on how collective decisions are made in animal groups.

According to study leader and ecology and evolutionary biology professor Iain Couzin, uninformed individuals can balance the influence of a vocal minority because they inhibit the minority’s attempt to manipulate the perception of what opinion is popular within the group. Instead, they respond quickly to numerical differences, allowing them to reinforce the majority opinion within the group.

The researchers turned to the golden shiner, a small species of fish that swims in schools, to run group decision-making experiments.

“We used schooling fish as one such ‘model’ of group behavior, since they are conveniently small and yet exhibit the coherent collective behavior we are familiar with,” Couzin said.

In the experiments, Couzin and his team established two groups: a minority group extremely committed to swimming towards a certain target and a majority group that was swimming in a different direction, but with less resolve. Because of the “time-consuming nature of the training,” the groups were small; the majority group had six fish, while the minority had five.

Since golden shiners tend to swim towards a yellow target, the researchers trained the majority group to swim towards a blue target, a behavior that they concluded would come less naturally to the group.

As expected, when the two groups were released together in a tank and allowed to swim towards a target, the old theory held true. The minority directed the group’s direction toward the yellow light.

But when the researchers introduced a third group of five untrained fish — meant to represent the uninformed individuals — the newcomers moved toward the blue light in accordance with the majority group, even though this behavior was not as natural.

This tendency increased when the size of the uninformed group was increased to 10 fish, though Couzin’s team noted that if too many uninformed individuals were present, the group would cease to behave coherently.

Though these findings might suggest that having some uninformed individuals is a good thing, Couzin explained that the uninformed tend to promote a democratic consensus in only specific situations, such as when there are “informational constraints” and “information is hard or expensive to acquire.”

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While the experiment focused on decision making in animals, Couzin explained that more general models they created showed similar dynamics, suggesting that “this principle may extend beyond the types of animals that [we] looked at,” he said.

But Couzin is reluctant to extrapolate his findings to explain human political behavior.

“We haven’t modeled human groups in our paper, and our results almost certainly do not relate to complex human politics, as has been suggested in some media articles,” he said.

So while the golden shiner experiment might not predict the results of the upcoming presidential election in November, Couzin said he believes that his findings might provide insight into the decision-making patterns of humans in committees, as well as other animal groups such as bird flocks.

“Our models suggest that this may be a principle we could find elsewhere in nature,” he said.

The report was published on Dec. 16 in the journal Science.