Category structure affects the developmental trajectory of children's inductive inferences for both natural kinds and artefacts

Abstract

Inductive reasoning is fundamental to human cognition, yet it remains unclear how we develop this ability and what might influence our inductive choices. We created novel categories in which crucial factors such as domain and category structure were manipulated orthogonally. We trained 403 4À9-yearold children to categorise well-matched natural kind and artefact stimuli with either featural or relational category structure, followed by induction tasks. This wide age range allowed for the first full exploration of the developmental trajectory of inductive reasoning in both domains. We found a gradual transition from perceptual to categorical induction with age. This pattern was stable across domains, but interestingly, children showed a category bias one year later for relational categories. We hypothesise that the ability to use category information in inductive reasoning develops gradually, but is delayed when children need to process and apply more complex category structures.

Ontological Constraints in Children's Inductive Inferences: Evidence From a Comparison of Inferences Within Animals and Vehicles

“…By the perceptual view, until about 6 years of age, induction is driven purely by perception and does not employ category knowledge. The reliance on categories is a late achievement requiring maturation, accumulation of knowledge, explicit training, and cognitive resources (Sloutsky and Fisher, 2004 ; Fisher and Sloutsky, 2005 ; Sloutsky et al, 2007 ; Sloutsky, 2010 ; Badger and Shapiro, 2015 ). According to the early knowledge view, young children's inferences employ rich category knowledge which is embedded in domain theories (Murphy and Medin, 1985 ).…”

“…Badger and Shapiro ( 2015 ) also compared inferences within animals and artifacts. They used artificial stimuli to ensure tight control over perceptual similarity across domains.…”

“…Based on these findings, Badger and Shapiro argue that the development of inductive inference proceeds in a domain-general fashion, and young children are not able to employ category knowledge in induction. Badger and Shapiro's ( 2015 ) findings are compelling, but they have some limitations. Unlike (Gelman and O'Reilly, 1988 ), who used multiple instances of natural kinds and artifacts as stimuli, Badger and Shapiro relied on a single basic-level distinction within each domain (rocky bug vs. desert bug, town trudge vs. country trudge).…”

“…It could be the case that their results do not generalize to other basic-level distinctions, for example, it is possible that vertebrate species elicit more category-consistent responses than insect species. Moreover, Badger and Shapiro's ( 2015 ) stimuli are artificial and it is not certain that the findings would be replicated with real-life entities (Gelman and Waxman, 2007 ).…”

“…While developmental theories of inductive inference describe how children reason about real entities, empirical studies present these entities as representations, such as videos (Jipson and Gelman, 2007 ), realistic photos (Tarlowski, 2006 ) or drawings of existing objects (Gelman and Markman, 1986 ), as well as depictions of inexistent entities (Sloutsky et al, 2007 ; Badger and Shapiro, 2012 , 2015 ). Relying on representations is an obvious and well justified methodological choice.…”