Eveningness is related to increased sociosexuality; having nocturnal short-term sexual strategies is an adaptive niche-exploiting behavior for both men and women that is governed by natural selection

Evening chronotype is associated with a more unrestricted sociosexuality in men and women. Robert L.Matchock. Personality and Individual Differences, Volume 135, 1 December 2018, Pages 56-59. https://doi.org/10.1016/j.paid.2018.06.054

Abstract: Chronotype and sociosexuality have been reported to be associated with each other and to also be sexually dimorphic. Specifically, research has suggested a link between evening chronotypes and increased sociosexuality, but the research is sparse, including the extent to which gender may interact with chronotype and sociosexuality. To that end, the present study administered the Horne and Ostberg morningness/eveningness questionnaire (MEQ) and the revised Sociosexual Orientation Inventory (SOI-R), which consists of behavior, attitude, and desire subscales, to 554 participants (61.7% female). Results indicated that men had a more unrestricted sociosexuality than women, except for the behavioral subscale. Eveningness was related to increased sociosexuality for both men (except the behavioral subscale) and women (for all subscales). It is suggested that adopting phase-delayed nocturnal short-term sexual strategies is an adaptive niche-exploiting behavior for both men and women that is governed by natural selection.

h/t: Rolf Degen https://twitter.com/DegenRolf