Past research has found that strongly opinionated members can determine a group’s consensus decision, even when they make up only a small minority.
But, the new research of animal behaviour now showed that adding ignorant or uninformed members to the group can counteract the minority’s powerful influence and promote a more democratic outcome, LiveScience reported.
For the study, published in the journal Science, a team at the Princeton University in the US used several computer models to investigate the decision-making process in various animal groups when a majority wants to travel in one direction and a minority wants to go in another.
When the strength of the two packs’ preferences was equal, the group was much more likely to follow the majority. But when the minority had stronger feelings than the rest of the group about its direction, it was able to control the decision, the researchers found.
When they added a third crowd that was ignorant of the options, the majority was able to spontaneously wrestle the decision back from the minority.“It’s very counterintuitive,” said Iain Couzin, who led the study. “We previously assumed that uninformed individuals promote extremism by being easily exploited by the [strong] minority.”
Couzin and his colleagues performed follow-up experiments with a school of freshwater fish to see how well their models apply to the real world. Using a group of golden shiners, the researchers trained two groups of the fish to associate a food reward with two different colour targets: one yellow, one blue.
The fish, like humans and other animals, have certain sensory biases, Couzin explained. Just as humans have an innate reaction to the colour red, golden shiners are naturally attracted to yellow, so the fish trained to expect food by following yellow dots were more strongly drawn to their target than those trained with blue dots.
When the researchers brought the two groups together and the yellow-target fish were in the minority (five yellow to six blue), the school of golden shiners followed the smaller group about 80 per cent of the time. But when the researchers added five untrained fish to the mix, the group chose the majority’s blue target half the time.
