Communication of gender from human breath odors: Relationship to perceived intensity and pleasantness

During five consecutive daily test sessions, 10 men and women rated the relative intensity and pleasantness of breath odors from 14 males and 19 females on a no-oral-hygiene regimen. In addition, the likely gender of the donor of each odor was also estimated. The breath odors of males were rated, on the average, as more intense and less pleasant than the breath odors of females. Women consistently gave lower pleasantness ratings to the odors than did men. Both the male and female judges assigned the breath odors to the correct gender classes at a frequency unlikely due to chance, although the females were more accurate in this regard. An inverse relation between breath odor intensity and pleasantness was noted. Systematic changes in the rated intensity and pleasantness of the odors were present across the 5 days of the study period. These data suggest that differences exist between the breath odors of men and women, and that humans, like many other mammals, may be capable of assessing gender from oral odors. However, such assignments conceivably reflect the strategy of assigning stronger and less pleasant odors to the male category, and weaker and less unpleasant odors to the female category, regardless of the true sex of the odor donor.