Behavioural flexibility is often treated as the gold standard of evidence for more
sophisticated or complex forms of animal cognition, such as planning, metacognition and
mindreading. However, the evidential link between behavioural flexibility and complex
cognition has not been explicitly or systematically defended. Such a defence is particularly
pressing because observed flexible behaviours can frequently be explained by putatively
simpler cognitive mechanisms. This leaves complex cognition hypotheses open to …