Lecture by Kees van Oers (NIOO-KNAW) and Marc Naguib (Wageningen UR).
From an evolutionary perspective you expect natural selection to favour one single optimal response to environmental challenges within the same population or species. Each individual flexibly adjusts its behaviour in response to changes in the environment. There is no difference in personality, only different behaviours in different circumstances. But how then can natural selection favour the evolution of multiple consistent responses to the same environmental conditions, resulting in within-population variation in many behavioural traits, meaning different personality types exist? Could there be more than one correct response to the same challenge? Or are there other reasons for the existence of variation in personality traits?