The global-to-basic level shift in infants’ categorical thinking: First evidence from a longitudinal study

This paper investigates whether preverbal children form categories at different levels of abstraction in any specific sequence. In a longitudinal study, 20 infants were each tested twice, at 8 and 12 months of age. Half of the children solved a global-level task (animals-furniture), followed by a basic-level task (either dogs-birds, or chairs-tables) during each session. The other half received the basic-level task only. During familiarisation, all infants freely explored a series of four different exemplars from the same category presented one at a time. Infants saw all objects twice, for a total of eight trials. During the test phase, a new exemplar from the familiar category was presented, followed by a different-category exemplar. At 8 months of age, children discriminated between categories in the global-level task, but failed to do so in the basic-level task. At 12 months of age, infants recognised a category change in the basic-level task, but treated both test items as equally new in the global-level task. These findings support the hypothesis that infants younger than 1 year of age show a global-to-basic-level shift in category formation.