Sexually speaking, the same 2006 study by Nordling et al. found that gay males were aware of their S/M preferences and took part in them at an earlier age, preferring leather, anal sex, rimming, dildos and special equipment or uniform scenes. In contrast, straight men preferred verbal humiliation, mask and blindfolds, gags, rubber/latex outfits, caning, vaginal sex, straitjackets, and cross-dressing among other activities. From the questionnaire, researchers were able to identify four separate sexual themes: hyper-masculinity, giving and receiving pain, physical restriction (i.e. bondage), and psychological humiliation. Gay men preferred activities that tended towards hyper-masculinity while straight men showed greater preference for humiliation, significantly higher master/madame-slave role play at ~84%. Though there were not enough female respondents to draw a similar conclusion with, the fact that there is a difference in gay and straight men suggests strongly that S/M (and BDSM in general) can not be considered a homogenous phenomenon. As Nordling et al. (2006) puts it, "People who identify as sadomasochists mean different things by these identifications." (54)