Children's knowledge of thematic and taxonomic relations at two years of age.

An interesting conflict exists in the developmental literature concerning the strength of thematic versus taxonomic associations. "Dog-doghouse" is a thematic match, while "dog-horse" is a taxonomic match. This study compared the ability of children to identify both types of associations at 2 points during the third year of life: 26 months (N = 15) and 34 months (N = 24). A reinforced match-to-sample technique was used in which half of the matches were thematic and the other half were taxonomic. Both age groups were able to identify thematic matches, although children near 3 years of age were able to recognize a wider range of thematic associations than children near 2 years of age. The 26-month-olds were unable to identify taxonomic matches that had no perceptual basis, but the 34-month-olds were successful at this task; the 34-month-olds appeared to have a more general understanding of categories that was less tied to perceptual features.