This study analyzed the relationship between urban and rural cultures and subjects' selection of attributes and groupings in a task of equivalence formation. Participants were 236 subjects, ages 6, 12, and 17, from rural and urban Argentina and from New York City. Subjects were administered an Equivalence Task consisting of two arrays of stimuli. Rural youngsters used less functional attributes and superordinate groupings than urban youngsters, at all ages. The performance of the urban youngsters in both cultures is significantly different in some aspects of the task; yet, they are closer to each other than either one is to the rural Argentinians. It would appear that some cultural factors, such as patterns of communications between the adults and children in the rural community, and the amount of schooling, among others, may partially explain some of the differences in the performances of rural and urban subjects. (Author)