The Role of Syntax and Contextual Frame in Children's Use of a Causal Theory in Reasoning about Natural Kinds

Abstract

A central focus of cognitive development research is the nature and organization of knowledge. Some researchers claim that young children use an intuitive theory to help them understand foundational domains such as biological categories. In particular, researchers have studied whether children's biological concepts are embedded in a causal theory about the nature of living organisms. Two key features of this theory are the concept of biological essences and the use of inductive generalizations. This study examined the influence of contextual frame and logical conjunctions on access and use of the theory in elementary and middle school children. It also investigated whether that causal theory supports both inductive and deductive reasoning. Children were given inductive and deductive tasks involving natural kinds. In the inductive tasks the child was asked whether a property of an animal would be found in other animals varying in taxonomic distance from the animal. In the deductive task, children worked on syllogisms based on cues at different levels of a biological taxonomy. Older children were not as likely to make inductions about instances of less biological resemblance to the target. However they also made more accurate deductions regardless of level of the hierarchy. Inductive and deductive performance were not correlated. Whether the cues were stated in a sentence beginning with "if" or "all" had no significant impact on performance, but whether the problem was presented from the viewpoint of a scientist or a pet store owner affected performance. These results were used to re-examine the basic tenets of essentialist thinking and the nature of developmental changes in reasoning about biological kinds.