Part-whole categorization is culture-specific

We present two experiments on the role of culture in the categorization of object part-whole structures. A triadic categorization task pitted shape against function as factors driving similarity judgments on selected parts of different types of objects. Speakers of American English were significantly more likely than speakers of two indigenous languages of Mexico, Tseltal Maya and Isthmus Zapotec, to choose categorization by function, even when familiarity of the various stimulus objects was factored in. In the second study, members of the two indigenous groups matched parts of a doll to parts of novel objects of unfamiliar shape. The Tseltal participants were significantly more likely to match according to a shape-analytical algorithm rather than global analogy, consistent with predictions based on prevalent strategies in verbal part labeling in the two languages. We conclude that while cognition of object parts undoubtedly has a strong biological basis, there are also robust cultural effects.