Reaction to “Basic objects in natural categories” by Rosch, Mervis, Gray, Johnson, & Boyes-Braem (1976)

Reaction to Rosch, Mervis, Gray, Johnson, & Boyes-Braem (1976) by Richard Thripp
EXP 6506 Section 0002: Fall 2015 – UCF, Dr. Joseph Schmidt
October 22, 2015 [Week 9]

This was a ground-breaking and lengthy study with multiple experiments designed to attack the issue of categories from several angles. Naturally, being 40 years old, the study can be criticized for many practices which were common at the time but frowned upon now, such as simply recruiting undergraduate students from the psychology department as participants. However, such issues are mitigated by the careful thought the authors have given to the messy issue that categorization is—such as in their discussions of the philosophical issues concerning superordinate, basic, and subordinate categories.

While the authors state that more than three categories are often in play, it would be nice to see them to address this in one of their experiments and to discuss it in more depth. Importantly, the biological taxonomies seemed significantly less useful and had to be excluded in Experiment 5 (p. 408). Their superordinate categories are basically “timeless,” such as fruit, trees, fishes, and birds, but were problematic; they were akin to the “basic” levels from categories such as musical instruments and clothing (pp. 392–393), though the latter may be more influenced by culture. However, even the biological and fruit taxonomies have a cultural component—obviously, different specimens of these categories appear on different continents, in different regions, and across different cultures. It is unfortunate the authors did not give due consideration to culture, though it is welcomed that they performed a speculative experiment regarding sign language (pp. 426–428).

One of the issues with recruiting homogeneous participants such as undergraduate psychology students is cohort effects. Even something as basic as common age can skew results—for example, participants in their early 20s might be more likely to identify clothing or vehicles differently than their parents, because they grew up in the 1960s and their parents probably grew up in the 1930s or 1940s. While it is definitely convenient, particularly when it is compulsory as in Experiment 6 (participants received “course credit,” not extra credit for their participation—what were the costs of declining to participate in terms of reduced grades?), I cannot see how researchers, even in the 1970s, could be blind to the issues it raises. It is alarming that even in Experiments 8 and 9, where the authors were methodologically compelled to recruit children, they still managed to find a place for their undergraduate students (pp. 416, 419)!

I was pleased to see that two and a half pages of discussion were dedicated to the effects of existing knowledge and expertise (pp. 430–432), since I was constantly thinking about this when reading the experiments, and the ichthyologist example (p. 393) was not satisfying. If the authors would have replaced airplanes with boats, would enthusiasts for each of these vehicles yield different results for these categories? Obviously, such differences should not be important in a heterogeneous, sufficiently large sample, but they are interesting enough to explore in their own right. Figure 4 (p. 431) is manifestly crude and pointless—obviously experts on a topic are going to have more intermediate categorization levels than laypersons. Consider that the present taxonomy for the classification of life has seven levels (domain, kingdom, phylum, class, order, genus, and species), and we can see that three levels might not represent the norm, but rather the bare minimum for a taxonomy. Intermediate levels are clearly evident even in the authors’ choices—in Table 1 (p. 388), even musically illiterate individuals can identify a class of categories between the superordinate category of “musical instruments” and the basic categories of individual instruments, consisting of categories such as strings, woodwinds, percussion, etc. The authors’ focus on the three-level superordinate–basic–subordinate paradigm eschews additional intermediate levels that are definitely present and probably important.

On a lighter, concluding note, it is rare that a typo can make me laugh out loud, but I would love to see a car equipped with a “food pedal” (p. 395).


Rosch, E., Mervis, C. B., Gray, W. D., Johnson, D. M., & Boyes-Braem, P. (1976). Basic objects in natural categories. Cognitive Psychology, 8, 382–439.

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