Building on previous work that identified different types of orgasm in human females (King, Belsky, Mah, & Binik, 2010), the goal of the present study was to extend such typological work and determine whether female orgasmic variability tracked potentially evolutionarily salient sexual partner characteristics (e.g. those displaying possible immune-system compatibility). Two-hundred and sixty-five females completed an Internet survey about their orgasmic experience -- achieved either with partners or alone. For partnered orgasms, they also provided details of partner characteristics and sexual behaviors. Latent class analysis revealed two orgasm types which were meaningfully distinguishable in terms of sensations and location—either centered on the surface of genitalia or deep inside. Deep orgasms were associated with internal sensations consistent with proposed functions of female orgasm in terms of differential sperm insuck. Such orgasms were associated with partners who were perceived as considerate, dominant, with a noticeably attractive smell, and as providing firm penetration. However, some hypothesized reproductively significant partner characteristics were not differentially associated with deep orgasms (i.e., muscularity, aggression, masculinity). Results are discussed and future research directions outlined.

Key words: Evolution, Female orgasm, Insuck, Oxytocin