Data from: A strong genetic correlation underlying a behavioural syndrome disappears during development because of genotype-age interactions

In animal populations, as in humans, behavioural differences between
individuals that are consistent over time and across contexts are
considered to reflect personality, and suites of correlated behaviours
expressed by individuals are known as behavioural syndromes. Lifelong
stability of behavioural syndromes is often assumed, either implicitly or
explicitly. Here, we use a quantitative genetic approach to study the
developmental stability of a behavioural syndrome in a wild population of
blue tits. We find that a behavioural syndrome formed by a strong genetic
correlation of two personality traits in nestlings disappears in adults,
and we demonstrate that genotype–age interaction is the likely mechanism
underlying this change during development. A behavioural syndrome may
hence change during organismal development, even when personality traits
seem to be strongly physiologically or functionally linked in one age
group. We outline how such developmental plasticity has important
ramifications for understanding the mechanistic basis as well as the
evolutionary consequences of behavioural syndromes.