The perception of gender in two allegedly sex-specific body odor compounds MSH and HMHA.

3-methyl-3-sulfanylhexan-1-ol (MSH) and 3-hydroxy-3-methylhexanoic acid (HMHA) are two allegedly sexually dimorphic compounds present in human sweat. While MSH is more typically found in women, HMHA is more typically found in men. Here we investigated whether it was possible to identify these two compounds as explicitly masculine or feminine. We also investigated whether gender and age differences would suggest a possible role of these compounds in mate preferences. To this end, we analyzed the perceptual ratings of t-shirts impregnated with these odors by 2,716 individuals (62% female) aged between 6 and 90, collected during a one-year museum exhibition. Analyses revealed that only women rated MSH as more feminine than HMHA. However, this effect remained very small and masculinity/femininity ratings were extremely variable among the population. Women also rated both odors as more intense and less pleasant than men. Age-related differences reflected the effect of increasing experience with body odors (familiarity). The loss of olfactory function with age was also reflected by decreased perceived intensity and unpleasantness (for HMHA). Overall, the results are not in favor of a role of MSH and/or HMHA in mate preferences, however they do agree with the known gender and age differences in odor perception.