Saturday, February 14, 2009

Lessons From Animal Behavior

A fascinating article from The Economist:


In a study reported in a special issue of the Philosophical Transactions of the Royal Society B, researchers led by Dr List looked at colonies of honeybees (Apis mellifera), which in late spring or early summer divide once they reach a certain size. The queen goes off with about two-thirds of the worker bees to live in a new home leaving a daughter queen in the nest with the remaining worker bees. Among the bees that depart are scouts that search for the new nest site and report back using a waggle dance to advertise suitable locations. The longer the dance, the better the site. After a while, other scouts start to visit the sites advertised by their compatriots and, on their return, also perform more waggle dances. The process eventually leads to a consensus on the best site and the swarm migrates. The decision is remarkably reliable, with the bees choosing the best site even when there are only small differences between two alternatives.

But exactly how do bees reach such a robust consensus? To find out, Dr List and his colleagues made a computer model of the decision-making process. By tinkering around with it they found that computerised bees that were very good at finding nesting sites but did not share their information dramatically slowed down the migration, leaving the swarm homeless and vulnerable. Conversely, computerised bees that blindly followed the waggle dances of others without first checking whether the site was, in fact, as advertised, led to a swift but mistaken decision. The researchers concluded that the ability of bees to identify quickly the best site depends on the interplay of bees’ interdependence in communicating the whereabouts of the best site and their independence in confirming this information.

This is something members of the European Parliament should think about. In the same journal, Simon Hix, also of the London School of Economics, and his colleagues examined their voting and concluded that, as might be expected, it was along party-political lines even though the incentives to do so were far less than at national parliaments. Dr Hix and his colleagues reckon that European parliamentarians share the collection of information but, unlike the honeybees, they do not necessarily progress to investigating the issues for themselves before taking a vote.

There is danger in blindly following the party line, a danger that the honeybees seem to avoid. Condorcet’s theory fails to consider whether there is an inbuilt bias among a group that comes together to consider a problem. This “groupthink” occurs when people copy one another. According to Dr List: “The swarm manages to block and prevent the kind of groupthink that can bedevil good decision making.” Dr List adds that people demonstrate this kind of bad decision-making when investors pile into a stock and others follow, creating a bubble for which there is no good reason.


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