A natural history of infidelity and a history of science on the topic. Listen and learn about the oldest known laws in history, fish that get pessismistic without their boyfriend, the costs of monogamy, the ovulatory shift hypothesis (and a conspiracy theory about it), the mate-switching vs. dual-mating debate, and so much more.

If you want to listen to my audio course on human evolution, you can find it here: https://mackenmurphy.gumroad.com/l/humanevolution?layout=profile

If you want to donate to support Species, you can do so, here: https://donorbox.org/keep-species-free

If you want to keep up with my work, everything is here: https://linktr.ee/mackenmurphy

Timestamps:

0:00 Intro

12:38 Theme

13:42 The Costs of Monogamy

20:01 The Many Strategic Functions of Infidelity

27:16 The Primary Reason Men Cheat

29:21 Intro to The Dual Mating Strategy

32:02 Ovulatory Shifts in Mate Preferences

34:26 Intro to the Mate Switching Hypothesis

36:13 Initial Impressions

42:15 Testing Mate-Switching vs. Dual-Mating

46:35 Addressing Critiques

48:16 The Usual Caveats

50:26 The Manosphere Reaction

51:31 Rollo's Conspiracy (lol)

55:01 Nature's Curse, Nature's Gift

58:15 Outro

Selected references (most key information is in, or referenced in, these texts): Murphy, M., Phillips, C. A., & Blake, K. R. (2024). Why women cheat: testing evolutionary hypotheses for female infidelity in a multinational sample. Evolution and Human Behavior, 45(5), 106595.

Buss, D. M., Goetz, C., Duntley, J. D., Asao, K., & Conroy-Beam, D. (2017). The mate switching hypothesis. Personality and Individual Differences, 104, 143-149.

Gangestad, S. W., & Thornhill, R. (1998). Menstrual cycle variation in women's preferences for the scent of symmetrical men. Proceedings of the Royal Society of London. Series B: Biological Sciences, 265(1399), 927-933.

Gangestad, S. W., Thornhill, R., & Garver-Apgar, C. E. (2005). Adaptations to ovulation: Implications for sexual and social behavior. Current Directions in Psychological Science, 14(6), 312-316.

Also:

Finkelstein, J. J. (1968). The Laws of Ur-Nammu. Journal of cuneiform studies, 22(3-4), 66-82.

Hicks, T. V., & Leitenberg, H. (2001). Sexual fantasies about one's partner versus someone else: Gender differences in incidence and frequency. Journal of Sex Research, 38(1), 43-50.

Laubu, C., Louâpre, P., & Dechaume-Moncharmont, F. X. (2019). Pair-bonding influences affective state in a monogamous fish species. Proceedings of the Royal Society B, 286(1904), 20190760.

Scelza, B. A. (2011). Female choice and extra-pair paternity in a traditional human population. Biology Letters, 7(6), 889-891.

Scelza, B. A. (2013). Choosy but not chaste: Multiple mating in human females. Evolutionary Anthropology: Issues, News, and Reviews, 22(5), 259-269.

Scelza, B. A. (2014). Jealousy in a small-scale, natural fertility population: The roles of paternity, investment and love in jealous response. Evolution and Human Behavior, 35(2), 103-108.

Stewart-Williams, S. "Nurture Alone Can't Explain Male Aggression." Nautilus. April 26, 2019. http://nautil.us/blog/nurture-alone-cant-explain-male-aggression

Yildiz, F. (1981). A tablet of codex Ur-Nammu from Sippar. Orientalia, 50(1), 87-97.