Data from: Brain size predicts behavioural plasticity in guppies (Poecilia reticulata): an experiment

Understanding how animal personality (consistent between-individual
behavioural differences) arises has become a central topic in behavioural
sciences. This endeavour is complicated by the fact that not only the mean
behaviour of individuals (behavioural type), but also the strength of
their reaction to environmental change (behavioural plasticity) varies
consistently. Personality and cognitive abilities are linked and we
suggest that behavioural plasticity could also be explained by differences
in brain size (a proxy for cognitive abilities), since accurate decisions
are likely essential to make behavioural plasticity beneficial. We test
this idea in guppies (Poecilia reticulata), artificially selected for
large and small brain size, which show clear cognitive differences between
selection lines. To test whether those lines differed in behavioural
plasticity, we reared them in groups in structurally enriched
environments, and then placed adults individually into empty tanks, where
we presented them daily with visual predator cues and monitored their
behaviour for 20 days with video-aided motion tracking. We found that
individuals differed consistently in activity and risk-taking, as well as
in behavioural plasticity. In activity, only the large-brained lines
demonstrated habituation (increased activity) to the new environment,
while in risk-taking, we found sensitization (decreased risk-taking) in
both brain size lines. We conclude that brain size, potentially via
increasing cognitive abilities, may increase behavioural plasticity, which
in turn can improve habituation to novel environments. However, the
effects seem to be behaviour-specific. Our results suggest that brain size
likely explain some of the variation in behavioural plasticity found at
the intra-species level.