LETTER

Exploring sexual orientation beyond genital arousal: Using large-scale online dating contact LETTER behavior to study male and female bisexuality Ho Fai Chana,b, Benno Torglera,b,c, and Stephen Whytea,b,d,e,1

Jabbour et al. (1) examine the extent to which men (12.47%) contacting men only compared with bisex- who self-report bisexual orientation exhibit bisexual ual women contacting women only (15.57%). When genital arousal, employing a larger sample than had exploring the contact behavior of bisexual men and been used in previous research (n = 588 who provided women according to their Kinsey scale (KS) (Fig. 1), self-reported arousal data; n = 474 with genital re- none of the respondents scoring between 0 and 5 sponses). The results confirm that men who report at- exhibits a difference in the distribution of contact traction to both sexes are also more genitally aroused by preferences between bisexual men or women (χ2 both sexes; therefore, they speculate that sample size tests, P > 0.1). The overall pattern of change in the and systematic differences between samples of bisexual relative share of contact types across the KS does ap- men (including miscategorization) may have contributed pear symmetrical for both sexes. However, the rate of to inconsistent results in previous studies. What the re- such difference across the spectrum is not (e.g., for KS = search in this field has so far failed to explore is how 1, 23.5% of bisexual males who contact women only are important insights can be generated beyond measure- not represented in KS = 5 by the 54.1% bisexual males ments of genital arousal or subjective orientation; for who contact men only). example, by exploring real-world online dating contact While miscategorization undoubtedly exists in the behavior as a way of measuring revealed preferences. bisexual male population, the fact that online dating Such data also offer the advantage of substantially larger contact behavior shows no statistically significant sex sample sizes than historical laboratory studies. difference suggests that it likely also exists in the Our dataset comprises online dating contact behav- bisexual female population, and that previous sex ior from 946 bisexual men and 623 bisexual women (2), difference findings relating to genital blood flow allowing us to go beyond just looking at male bisexu- assessments and their association with sexual orienta- ality. Jabbour et al. (1) in fact stress how “converging tion may be problematic (3, 4). That Jabbour et al. (1) lines of evidence suggest that there are important dif- excluded 26.73% of bisexual males for “insufficient ferences in the expression of male and female sexual genital arousal for meaningful analysis” (p. 18375) orientation, perhaps especially bisexuality” (p. 18370). speaks to such issues. This therefore suggests the im- However, by simply exploring the distribution of bisex- portance of mixed methods to understand bisexual ual online dating participants who prefer to contact ex- orientation and alternative proxies for arousal and clusively 1) same sex only, 2) opposite sex only, and 3) revealed preferences. As Zivony (5) argues, the com- both sexes, we find no statistically significant difference plexity of sexual orientation cannot be reduced to between bisexual men and women (n = 1,569; χ2 test: genital arousal. However, contrary to Zivony (5), we P = 0.166). In fact, we find relatively more bisexual encourage sexual orientation scientists to look be- men (74.52%) contacting both sexes compared with yond subjective measures and utilize the plethora of bisexual women (70.63%), and fewer bisexual men new field data available.

aSchool of Economics and Finance, Queensland University of Technology, Brisbane, QLD 4001, Australia; bCentre for Behavioural Economics, Society and Technology, Queensland University of Technology, Brisbane, QLD 4001, Australia; cCenter for Research in Economics, Management, and the Arts, CH-8008 Zurich, Switzerland; dCentre in Regenerative Medicine, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD 4059, Australia; and eAustralian Research Council Training Centre for Cell and Tissue Engineering Technologies, Queensland University of Technology, Brisbane, QLD 4059, Australia Author contributions: H.F.C., B.T., and S.W. designed research, performed research, analyzed data, and wrote the paper. The authors declare no competing interest. This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND). 1To whom correspondence may be addressed. Email: [email protected]. Published March 15, 2021.

PNAS 2021 Vol. 118 No. 12 e2026320118 https://doi.org/10.1073/pnas.2026320118 | 1of2 Downloaded by guest on October 1, 2021 Fig. 1. Bisexual men/women contact according to their Kinsey scale.

1 J. Jabbour et al., Robust evidence for bisexual orientation among men. Proc. Natl. Acad. Sci. U.S.A. 117, 18369–18377 (2020). 2 S. Whyte, R. C. Brooks, B. Torgler, Sexual economic theory & the human mating market. Appl. Econ. 51, 6100–6112 (2019). 3 J. M. Bailey et al., Sexual orientation, controversy, and science. Psychol. Sci. Public Interest 17,45–101 (2016). 4 B. A. Feinstein, M. P. Galupo, Bisexual orientation cannot be reduced to arousal patterns. Proc. Natl. Acad. Sci. U.S.A. 117, 31575–31576 (2020). 5 A. Zivony, Bisexuality in men exists but cannot be decoded from men’s genital arousal. Proc. Natl. Acad. Sci. U.S.A. 117, 31577–31578 (2020).

2of2 | PNAS Chan et al. https://doi.org/10.1073/pnas.2026320118 Exploring sexual orientation beyond genital arousal: Using large-scale online dating contact behavior to study male and female bisexuality Downloaded by guest on October 1, 2021