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.
- I.D. Couzin et al, Science, 334, 1578, (2011).
- http://www.bbc.co.uk/news/science-environment-16206336
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