What are the developmental origins of our concept of animal? There has long been controversy concerning this question. At issue is whether biological reasoning develops from earlier forms of reasoning, such as physical and psychological reasoning, or whether from a young age children reason about animals biologically. If there is a core biological domain, it may have its origins in infancy, and expectations about insides and animal behaviors are likely candidates for early biological expectations. First, I focus on animals’ insides and ask whether infants expect that the removal of an animal’s insides should lead to the loss of function, and more specifically the loss of self-propulsion (Experiment 1). Second, I am interested in whether infants know about behaviors that all animals share. I use an inductive over-hypothesis approach: if infants view certain animal behaviors as privileged, then small amounts of evidence that an animal of a kind engages in a specific behavior may lead to rapid generalization of the same behavior to the entire kind. Using this generalization method, I investigate infants’ expectations about two kind-specific behaviors of animals: having the same diet (Experiments 2-3) and producing the same sounds to communicate (Experiments 4-5). In Experiments 2 and 3, 15- month-olds expect animals of the same kind (as indicated by shape similarity) to share food preferences – a kind relevant property, but not the same toy preferences – a kind irrelevant property. These contrasting results suggest that infants did not simply expect similar objects to share similar non-obvious properties. Rather, their expectations were driven in part by a biological framework that views diet, but not toys, as biologically relevant. In Experiments 4 and 5, 15-month-olds expect animals of the same kind to make the same types of sounds, but do not have similar expectations for animals of two distinct kinds, or two similar shaped non-animal objects. These experiments thus provide converging evidence that self-propulsion and agency (demonstrated by having a food preference or vocalizing contingently) together signal the ontological status of animal, and that infants’ conceptual knowledge in turn guides their reasoning and generalizations about animals’ biologically relevant behaviors. Positive evidence in these experiments supports the biological hypothesis that infants may have a distinct biological domain, and may immediately ascribe to entities identified as animals additional properties that are biological in nature.
Infant Cognition, conceptual development, biological reasoning
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign