Graded structure in odour categories: A cross-cultural case study

The existence of graded structure in fruit and flower odour categories and its stability in different cultures is examined. Groups of students from France, the United States, and Vietnam performed a typicality rating task, a similarity judgment task, a membership verification task, a recognition memory task, a familiarity rating task, and a free identification task using a set of 40 odorants (20 fruit odorants and 20 flower odorants). Overall, our results demonstrate that fruit and flower odour categories possess graded structure. Moreover, principal component analyses of the data revealed the implication of typicality in a variety of cognitive tasks where typical odours receive a preferential processing compared to atypical ones. Finally, our results suggest that typicality can be predicted to a certain extent by experiential knowledge but that other determinants play a role in odour category structure. Altogether, this study confirms that graded structure is a universal property of categories and suggests that universals and cultural specifics can both constrain the emergence of odour category structures.