Olfactory discrimination of mouse strains (Mus musculus) and major histocompatibility types by humans (Homo sapiens

A series of experiments revealed that humans can use olfaction to discriminate closely related strains of mice, differing genetically only at the major histocompatibility gene complex (H-2). In Experiment 1, subjects were asked to distinguish between the whole-body odors of live mice. In Experiments 2 and 3, the odor source was mouse fecal pellets, and in Experiments 4 and 5, the odor source was mouse urine. How well can people discriminate nonhuman odors of mammalian origin? This question arises frequently, often in the course of invidious comparisons of the perceptual acuity of human and nonhuman mammals. There is, however, a more substantial question on which it bears, namely, the role of olfaction in animal social behavior and the extent to which exchange of information in the olfactory modality constitutes an evolved system of communication. One test by which a system is judged to serve a communicatory function is the criterion o