A Princeton University-based research team, led by Professor Iain Couzin, reports that this finding – based on group decision-making experiments on fish, as well as mathematical models and computer simulations – can ultimately provide insights into humans’ political behaviour.

The researchers, who include Dr Christos Ioannou and Dr Thilo Gross at the University of Bristol, report that in animal groups, uninformed individuals – those with no prior knowledge or strong feelings on a situation’s outcome – tend to side with and embolden the numerical majority.  Relating the results to human political activity, the study challenges the common notion that an outspoken minority can manipulate uncommitted voters.

“The classic view is that uninformed or uncommitted individuals may allow extreme views to proliferate.  We found that might not be the case,” said Professor Couzin.  “We show that when the uninformed participate, the group can come to a majority decision even in the face of a powerful minority.  They prevent deadlock and fragmentation because the strength of an opinion no longer matters – it comes down to numbers.  You can imagine this being a good or bad thing.  Either way, a certain number of uninformed individuals keep that minority from dictating or complicating the behaviour of the group.”

However, this effect has its limits.  The researchers found that if the number of uninformed becomes too high, a group ceases to function coherently, with neither the majority nor the minority taking the lead. 

The study was based on experiments conducted by Dr Ioannou on golden shiners, a fish prone to associating the colour yellow with a food reward.  Some of the golden shiners were trained to swim toward a blue target, while smaller groups were trained to follow their natural predilection for a yellow target.  When the two groups were placed together, the minority's stronger desire for the yellow target dominated the group's behaviour.  As fish with no prior training (the uninformed individuals) were introduced, however, the fish increasingly swam toward the majority-preferred blue target.

“We think of being informed as good and being uninformed as bad, but that’s a human construct.  Animal groups are rarely in a fractious state and we see consensus a lot,” said Professor Couzin.  “These experiments indicate there is an evolutionary function to being uninformed that perhaps is as active as being informed.  Animals may be equally adaptable to simply going with the majority in certain circumstances because having that quick decision-making capability is beneficial for survival.  We shouldn't think of it as a bad thing, but look at advantages animals exhibit to being uninformed in natural circumstances.”

The researchers also developed mathematical models and computer simulations that revealed and described how uninformed individuals restore popular power.  In the computer models, consensus emerged once uninformed individuals were introduced.  There was a sharp transition from minority to majority control.  At a certain threshold, only a few uninformed individuals could alter the entire outcome of group decisions.

Mathematical models, one created by Dr Gross with Dr Güven Demirel of the Max Planck Institute and one by Dr Colin Torney at Princeton, helped explain the mysterious pull of the uninformed individuals.  These models were based on social processes in human groups, such as how conventions become established, or how people influence each other's opinions.

The calculations indicated that during the decision-making process, all individuals have a tendency to follow what they perceive as the predominant view, but opinionated individuals are more resistant to social pressure.  This reluctance to compromise manipulates the perception of what is popular, meaning that the strong convictions of the minority can make their view seem dominant.  Uninformed individuals, having no strong opinion or preference, tend to inhibit this process because they respond quickly to numerical rather than semantic differences and curb the influence of forceful individuals.

Paper

‘Uninformed Individuals Promote Democratic Consensus in Animal Groups' by Iain D. Couzin, Christos C. Ioannou, Güven Demirel, Thilo Gross, Colin J. Torney, Andrew Hartnett, Larissa Conradt, Simon A. Levin, Naomi E. Leonard in Science

Iain Couzin worked with, from Princeton, second author Christos Ioannou, a former postdoctoral fellow in Couzin's lab who is now a research fellow at the University of Bristol; postdoctoral researcher Colin Torney and doctoral student Andrew Hartnett, both in Couzin's lab; and professors Simon Levin, the Moffett Professor of Biology, and Naomi Leonard, the Edwin S. Wilsey Professor of Mechanical and Aerospace Engineering.

The team also included Güven Demirel, a researcher at the Max Planck Institute for the Physics of Complex Systems; Thilo Gross, an engineering lecturer at the University of Bristol; and Larissa Conradt, a visiting researcher at the University of Cambridge.

The research was supported by grants from the National Science Foundation, the Searle Scholars Program, the US Navy Office of Naval Research, the Royal Society and the Defense Advanced Research Projects Agency administered by the US Department of Defense.