Basic-level superiority in picture categorization

In a seminal paper, E. Rosch, C. B. Mervis, W. D. Gray, D. M. Johnson, and P. Boyes-Braem (Cognitive Psychology, 1976, 8, 382-439) found that an object can be categorized faster at the basic level (e.g., hammer) than at either a subordinate (club hammer) or a superordinate level (tool); they attributed this result to basic categories having more distinctive attributes. But numerous factors other than the number of distinctive attributes might have caused this result; for example, basic categories routinely have shorter and more frequent names than do subordinates, and are typically learned earlier and occur more often than either subordinate or superordinate categories. In this paper, we report three experiments, all of which used artificial subordinate, basic, and superordinate categories, and all of which either held constant or systematically varied several of these "other" factors. All three studies replicated the finding that objects can be categorized fastest at the basic level (but the relative speeds of subordinate and superordinate categorizations differed from past results); and all three strongly supported the claim that distinctive attributes are the factor underlying the results, though it appears that only perceptual attributes are critical.