Complex dynamics and development of behavioural individuality

Consistently finding consistent differences Animals in a population frequently display consistent among-individual differences in their behaviours (Bell, Hankison, & Laskowski, 2009; D. S. Wilson, 1998). Among-individual differences in behaviour have long been considered important as such differences are required for natural selection to cause mean individual behaviour to change. Indeed, in the last few decades increased interest in these differences has spurred the generation of the field of “animal personality”. A key element of this recent surge has been to identify the processes that lead to and maintain amongindividual behavioural differences. Correlations with more stable physiological or motivational states (Sih et al., 2014) or life-history traits (Réale et al., 2010), or the role of environmental factors (Kortet, Hedrick, & Vainikka, 2010; Montiglio & Royauté, 2014) have all been investigated to explain why animals in the same population show consistent differences in mean behaviour across contexts (Dingemanse & Wolf, 2010; Kight, David, & Dall, 2013). These explanations typically require there to be variation in some other factor, be that genetic or environmental in origin, which then drives among-individual differences in behaviour (but see: Luttbeg & Sih, 2010; Mathot, Dekinga, & Piersma, 2017; Sih et al., 2014).