Inferring unseen causes : exploring the developmental and evolutionary origins

Abstract

Human adults excel at inferring and exploiting the causal relations in the world. This certainly contributed to the unprecedented advancements in many areas of life from technology to health and astronomy, not seen in other non-human species. What might have led to this capacity? Is the ability to identify causal relations a uniquely human ability? When does it emerge in human development? Do we represent our environments in fundamentally different ways than other non-human animals? In this thesis, I aimed to expand our understanding concerning these questions. If this is a core human capacity, we may find its precursors in other non-human primates. On the other hand, it may be a late emerging capacity in childhood with the development of language and through cultural input. Then there may not be a continuity with other primates.

In my theoretical chapters, I brought together the previous literature to identify the factors that might have facilitated and/or hampered children’s and non-human primates’ performances while they were dealing with causal reasoning tasks. In the light of the challenges presented by this type of research and my goals, I proposed novel paradigms that are suitable to test causal reasoning abilities of young children, chimpanzees and capuchin monkeys.

In three studies, I found that by 4-years of age children were able to infer causal relations based on evidence alone. Three-year-olds did not succeed in the tasks but seemed to have benefited from verbal scaffolding provided by the experimenter. The performance of the chimpanzees and capuchins did not lead to decisive conclusions towards the lack or the presence of this capacity. However, the findings highlighted the importance of prior experience in animal learning. The results and their implications are further discussed.