Abstract
The drivers of differences in cognitive ability, within as well as across species, remain a debated "hot-topic" in animal cognition. Current hypotheses link variation in sociality, ecology, and more generally, environmental challenges to differences in cognition. Research supporting the social intelligence hypothesis, which states that cognition evolved to deal with the challenges of interacting with conspecifics, is largely focused on highly social mammal and bird species, limiting our ability to evaluate the general applicability of the hypothesis. Furthermore, it is unclear whether the social environment facilitates cognitive development or if selection acts against individuals with low cognitive abilities in social groups. Unfortunately, developmental studies which can reveal the causal link between early life experiences and cognitive development are scarce. Therefore, we aimed to test the effect of the early post-natal social environment on the development of behavior and cognition in a social lizard, the tokay gecko (Gekko gecko). Our results show that the early social environment influenced the development of boldness and the variation in space neophobia and associative learning. We discuss our findings in the light of the social intelligence hypothesis, taking into account the facultative social nature of our study system.