Abstract
The ability to make inductive inferences is important because without it, generalization of knowledge to new circumstances would be impossible. One context in which such inductive skills are likely to have been important over evolutionary time is encounters with animals. Previous research suggests that children take into account at least two kinds of relationships between animals when making inductive inferences about them: descent relationships, and design relationships. Because descent and design relationships are sometimes orthogonal, making correct inferences about particular traits sometimes requires overlooking one kind of relationship in favor of the other. In this study, I used a base-to-target induction task to examine the use of two inference rules in 5 to 12 year old Shuar children from the Amazon region of Ecuador. The descent rule uses taxonomic relationships when the function of the trait being judged is ambiguous or unknown, and the design rule privileges ecological relationships over taxonomic relationships when the function of the trait is relevant to the ecological category in question. The results show that Shuar children do employ both of these rules, and are able to switch between them for different kinds of traits, as the descent/design mode hypothesis predicts. Children in both the younger age group and the older age group were able to use these rules, but the older children showed a slightly different pattern due to the use of specific acquired knowledge about some of the taxa.