Smell and Social Behavior In a PET study, heterosexual women, homosexual men, and heterosexual men were scanned as they were presented with each of several odors. During the presentation of a testosterone-based odor (referred to in the figure as AND), there was significant activation in the hypothalamus for heterosexual women (left) and homosexual men (center) but not for (right) heterosexual men (Savic et al., 2005).

IVANKA SAVIC, HA BERGLUND, AND PER LINDSTROM