Laughter and ratings of funniness in speed-dating do not support the fitness indicator hypothesis of humour

Individuals consistently report preferring humour in a romantic partner; but it is unclear why. The ‘fitness indictor hypothesis’ proposes that attraction to humour evolved because it is an indicator of genetic fitness. Studies testing predictions from this hypothesis, mostly based on stated preferences regarding a hypothetical ideal partner or on artificial tasks or scenarios, have so far yielded conflicting evidence. Here, we assessed a sample of 554 participants' (291 women) stated preferences for various traits including humour production and receptiveness, and their revealed preferences for the same traits through speed dates (i.e. a naturalistic, face-to-face setting). Dates were audio-recorded for a subset of 350 participants (188 women), enabling additional assessment of revealed preferences based on an objective measure of humour in the form of laughter frequency. We tested the predictions that 1) humour is an attractive trait, and 2) men are more attracted to humour receptivity compared to women, and women are more attracted to humour production compared to men. Stated preferences from men and women largely replicated those found in the existing literature and are consistent with the fitness indicator hypothesis. Results from revealed preferences found a main effect of funniness on ratings of overall partner attractiveness, but there was no significant effect of laughter on attractiveness. Revealed preferences, using both funniness ratings and laughter, also found no main effect of humour receptivity on overall attractiveness. Finally, we observed no sex differences in the effects of humour production and humour receptivity, as measured by both funniness ratings and laughter, on ratings of overall attractiveness.