More Evidence and Context Are Needed to Evaluate the Possibility That Scent Perception Is Part of the Same-Sex Sexual Behavior Story

  • Brendan P. ZietschEmail author

Pfau, Jordan, and Breedlove (2019) present a fascinating—though, in their own words, tentative—hypothesis regarding the evolution of same-sex sexual behavior. In their perspective, the loss of functionality of the transient receptor potential cation channel 2 (TRPC2) gene around 25 million years ago allowed for same-sex sexual behavior in catarrhine species (including apes and Old World monkeys) by removing a pheromonal process that had directed sexual behavior exclusively toward the opposite sex. I welcome Pfau et al.’s proposal and appreciate that they have framed their Target Article as a call for other researchers to explore ways to test it.

A fundamental question that the Target Article provokes is whether the hypothesis is either broad enough—when considering same-sex sexual behavior in nature—or specific enough—when considering human same-sex sexual behavior. Same-sex sexual behavior has been documented in hundreds of species, including mammals, birds, reptiles, and even insects...



Brendan Zietsch is supported by a Future Fellowship (FT160100298) from the Australian Research Council.


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© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Centre for Psychology and Evolution, School of PsychologyUniversity of QueenslandBrisbaneAustralia

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