BoundedRationality_TheAdaptiveToolbox.pdf

Imitation, Social Learning, and Preparedness as Mechanisms 239
Unfortunately, the assumptions and conclusions of these theoretical analyses
have not been subject to a great deal of empirical investigation. However,
Laland and Williams (1998) have carried out an experiment designed to test the
theoretical prediction that social learning should be maladaptive in an environment
with rapid or sudden changes. Populations offish were established with
socially transmitted traditions for taking different routes to a food source by
training founders to take particular routes and then gradually replacing the
trained animals with naive fish. In the experimental tanks there were two routes,
with one route substantially longer than the other. The long route was designed
to represent an environment in which the optimal route to feed had suddenly
changed, thus fish in shoals whose founders were trained to take the long route
have to learn to "track this change" by switching preference to the short route.
The experiment found that swimming with founders that had a prior preference
for the long route slowed down the rate at which subjects adjusted to the new pat
terns of reinforcement in their environment, relative to fish that swam alone (see
Figure 13.2). Consistent with the theoretical predictions, shoaling fish utilizing
public information tracked the environment less effectively than lone fish. If this
finding applies to natural populations of animals, where behavioral traditions
lag behind the environmental state, the lag may be greater for animals that aggregate
and rely on social information than it would be for isolates relying exclusively
on their own experience. If this is the case, suboptimal traditions may be
fairly common in animal populations.
The findings of this experiment should be interpreted with some caution.
While the experiment can legitimately be described as providing evidence for
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Shoaling fish
Lone fish
Figure 13.2 Fish that swam with conspecifics that had a preestablished preference for
a circuitous route to a food source learned to take a short route more slowly than fish that
swam alone. This suggests that animals utilizing public information may sometimes
track the environment less effectively than loners. Figure reprinted with permission from
Oxford University Press; taken from Laland and Williams (1998).