Figure 7.3: A sex difference in olfactory ability When women and men were tested in repeated sessions for their ability to smell weak concentrations of benzaldehyde (an almond-cherry smell) and citralva (an orange-lemon smell), the women but not the men showed dramatic improvement. By the eighth session, the women’s absolute threshold for citralva was more than five log units less than that of the men. In other words, the women were smelling this substance at concentrations less than one hundred-thousandth of the minimal concentration that the men could smell.
(Based on data from Dalton et al., 2002.)