Smell and Social Behaviour In a PET study, heterosexual women, homosexual men, and heterosexual men were scanned as they were presented with each of several odours. During the presentation of a testosterone-based odour (4,16-androstadien-3-one, [AND]), there was significant activation in the hypothalamus for heterosexual women (left) and homosexual men (centre) but not for heterosexual men (right) (Savic et al., 2005).

IVANKA SAVIC, HA BERGLUND, AND PER LINDSTROM