Something Fishy At The Polls

Elections have been going on all over the world this year and the US is now braced for the Republican circus in preparation for next November’s three-ring event. So democracy is being exercised all over the place, but there are a lot of variations of ‘democracy,’ some of which are more transparent than others. The problem is that powerful minorities mount campaigns that are difficult to stop once the momentum is built in any social group.

 Indecision is not a good thing for a social group any more than the lack of ability to make a decision, so we must have some among us who think they know which way to go and want to take us along whether we are a group of social insects, a flock of birds, a shoal of fish or Congress.

The group decision-making process is a nice problem for those with big computers and a penchant for simulation. The latest to try their hand at this is the group of Couzin et al whose results are published in Science (1, 2).

Their model used vector algebra where an individual’s determination was modeled as the magnitude of a ‘force’ directed towards a particular target (goal). The question was how often strongly opinionated individuals would take the majority away from their target.

So far, this is just a matter of which group have the loudest collective voice locally and the strongly opinionated individuals punched well above their weight – a result we are all familiar with. But to make it exciting, they introduced a wild card in the form of a third population of uninformed individuals who didn’t have a clue as to where they should go

The exciting result came as the fraction of uninformed in the population increased, the majority regained control of their direction towards their target. The simulation came with a warning though. If the uninformed became too large a fraction of the population, chaos and indecision resulted.

Like any good scientists, the team had to test this result with real live actors, so they held auditions and picked a shoal of freshwater fish – Notemigonus crysoleucas otherwise known as golden shiners by the fisherman who use them for bait. The shoal was split into three populations. One population was shown a yellow target where there was food. The second, larger, was trained to a blue target for food. The third population was the uninformed.

As these fish have a prevalence for yellow, those who were trained to find food at the yellow target were therefore strongly opinionated individuals. The results were as predicted by the simulations. A few ‘yellows’ dragged the ‘blues’ along to the yellow target. But democracy returned when the great uninformed were added into the mix as the ‘blues’ regained control of the tank.

  1. I.D. Couzin et al, Science, 334, 1578, (2011).

Please note that this blog is migrating to
in 15 days.

Leave a Reply