University of Lethbridge

About Me

Paul L. Vasey is a Professor and a Board of Governor's Research Chair who conducts cross-species and cross-cultural research on sexuality and gender. Since 2000, he has conducted research on the development and evolution of female homosexual behavior in free-ranging Japanese monkeys at various sites in Japan. Since 2003, he has worked in Samoa with members of the fa'afafine community—feminine, same-sex attracted males who adopt non-binary gender identities. Since 2015, he has worked in the Istmo region of Oaxaca, Mexico, with members of the muxe community—cisgender (muxe nguiiu) and transgender (muxe gunaa) same-sex attracted males who adopt non-binary gender identities. Dr. Vasey has published over 100 scientific articles based on research conducted at these fieldsites. His research has been funded by the Natural Sciences and Engineering Research Council of Canada, the Social Sciences and Humanities Research Council of Canada, the Canadian Institute of Health Research, Alberta Innovates Health Solutions, the National Institute of Health (USA), the American Institute of Bisexuality, and the Leakey Foundation.

Dr. Vasey is a Associate Editor of the Archives of Sexual Behavior. His work has been the subject of various documentaries on television (e.g., National Geographic, Discovery Channel, Nature of Things) and the radio (e.g., U.S National Public Radio, Canadian Broadcasting Corporation, Radio Netherlands) and has been reported on in hundreds of newspapers and magazines such as the New York Times, Oprah and TIME.

Selected Publications

(last six years)

2021

Goméz Jiménez, F.R. & Vasey, P.L.
Facial attractiveness of the sisters of Istmo Zapotec men and muxes: Implications for the evolution of male androphilia. Journal of Sex Research, 59, 354-359.

Goméz Jiménez, F.R., Court, L., & Vasey, P.L.
Occupational preferences and recalled childhood sex-atypical behavior among Istmo Zapotec men, women, and muxes. Human Nature, 32, 729-747.

Semenyna, S. W., Gómez Jiménez, F. R., & Vasey, P. L.
Testing women's trust in other women and same-sex attracted males in three cultures. Archives of Sexual Behavior, 50, 3479-3488.

Semenyna, S. W., Gómez Jiménez, F. R., & Vasey, P. L.
Women's reaction to opposite- and same-sex infidelity in three cultures: Data from Canada, Samoa, and the Istmo Zapotec. Human Nature, 32, 450-469.

Gómez Jiménez, F. R. & Vasey, P. L.
Muxes. In A. Goldberg & G. Beemyn (Eds.), The SAGE encyclopedia of trans studies (Vol. 2), pp. 556-558. Thousand Oaks, CA: SAGE Publications, Inc.

Blanchard, R., Beier, K.M., Gómez Jiménez, F.R., Grundmann, D., Krupp, J., Semenyna, S.W., & Vasey, P.L.
Meta-analyses of fraternal birth order effects in homosexual pedophiles, hebephiles, and teleiophiles. Archives of Sexual Behavior, 50, 779-796.

Petterson, L.J. & Vasey, P.L.
Samoan men's sexual attraction and viewing time response to Male-to-Feminine transgender and cisgender adults. Archives of Sexual Behavior, 50, 873-884.

Semenyna, S. W., & Vasey, P. L.
Women's trust in gay men: An experimental study. Personality and Individual Differences, 175, 110727.
https://www.sciencedirect.com/science/article/pii/S0191886921001021?dgcid=author

Petterson, L.J. & Vasey, P.L.
Canadian undergraduate men's visual attention to cisgender women, cisgender men, and feminine trans individuals. Scientific Report, 11, 388; https://doi.org/10.1038/s41598-020-79870-2


2020

Gunst, N., Vasey, P.L., & Leca J-B.
Is female-male mounting functional? An analysis of the temporal patterns of sexual behaviors in Japanese macaques. Physiology & Behavior, 223, 112983. https://doi.org/10.1016/j.physbeh.2020.112983

Gómez Jiménez, F.R., Semenyna, S.W. & Vasey, P.L.
The relationship between fraternal birth order and childhood sex-atypical behavior among the Istmo Zapotec muxes. Developmental Psychobiology, 62: 792-803.

Semenyna, S.W., Gómez Jimenez, F. & Vasey, P.L. Inter-sexual mate competition in three cultures. PLoS ONE. https://doi.org/10.1371/journal.pone.0236549

Blanchard, R., Krupp, J., VanderLaan, D.P., Vasey, P.L., & Zucker, K.J.
A method yielding comparable estimates of the fraternal birth order and female fecundity effects in male homosexuality. Proceedings of the Royal Society B,
287(1923), 20192907. https://doi.org/10.1098/rspb.2019.2907

Gómez Jiménez, F.R, Court, L. & Vasey, P.L.
A retrospective study of childhood gendered behavior in Istmo Zapotec men, women and muxes. Archives of Sexual Behavior, 49: 467-477.

Petterson, L.J., Dixson, B.J., Little, A.C. & Vasey, P.L.
Heterogeneity in the sexual orientations of men who have sex with fa'afafine in Samoa. Archives of Sexual Behavior, 49: 517-529.

Gómez Jiménez, F.R., Semenyna, S.W. Court, L., & Vasey, P.L.
Offspring production among the relatives of Istmo Zapotec men and muxes. Archives of Sexual Behavior, 49: 581-594.

Rahman, Q., Xu, Y., Lippa, R., & Vasey, P.L.
Prevalence of sexual orientation across 28 nations and its association with gender equality, economic development, and individualism. Archives of Sexual Behavior, 49: 595-606.

Vasey, P.L., Petterson, L.J., Semenyna, S.W., Gómez, F.R. & VanderLaan, D.P. Kin selection and the evolution of male androphilia. In: Workman, L., Reader, W. & Barkow, J. (eds.), Cambridge Handbook of Evolutionary Perspectives on Human Behavior, pp. 366-377. Cambridge, UK: Cambridge University Press.


2019

Semenyna, S. & Vasey, P.L.
Prestige striving in Samoa: A comparison of men, women and fa'afafine. Journal of
Homosexuality, 66: 1535-1545.

Semenyna, S. W., Vasey, P. L., & Honey, P. L.
Replicating the relationships between Dark Triad traits and female mate competition tactics in undergraduate women. Personality and Individual Differences, 147: 73-78.


2018

Petterson, L.J, Dixson, B.J., Little, A.C., Vasey, P.L.
Viewing time and self-report measures of sexual attraction in Samoan cisgender and transgender androphilic males. Archives of Sexual Behavior, 47: 2427-2434.

Leca, J-B., Shimizu, K., Huffman, M.A., Takahata, Y., Gunst, N., & Vasey, P.L.
Hormonal contraceptive affects heterosexual but not homosexual behavior in free-ranging female Japanese macaques over 17 mating seasons. Hormones & Behavior, 105: 166-176.

Gunst, N., Vasey, P.L. & Leca, J-B.
Deer mates: A quantitative study of heterospecific sexual behaviors performed by Japanese macaques toward sika deer. Archives of Sexual Behavior, 47: 847-856.

Petterson, L.J, VanderLaan, D.P., Persson, T.J. & Vasey, P.L.
The relationship between indicators of depression and anxiety and sexual orientation in Canadian women. Archives of Sexual Behavior, 47: 1173-1182.

Gómez, F.R., Semenyna, S., Court, L. & Vasey, P.L.
Familial clustering of male androphilia among Istmo Zapotec men and muxe. PLoS ONE, 13(2): e0192683.

Semenyna, S. W., Belu, C. F., Vasey, P. L., & Honey, P. L.
Not straight and not straightforward: Sexual orientation, sociosexuality, and Dark Triad traits among women. Evolutionary Psychological Science, 4: 24-37.


2017

Playà, E., Vinicius, L. & Vasey, P.L.
Need for alloparental care and attitudes toward homosexuals in 58 countries: Implications for the kin selection hypothesis. Evolutionary Psychological Science, 3: 345-352.

Semenyna, S.W., Patterson, L.J. & VanderLaan, D.P. & Vasey, P.L.
Familial patterning and prevalence of male androphilia in Samoa. Journal of Sex Research, 54: 1077-1084.

Semenyna, S.W. & Vasey, P.L.
Bullying, physical aggression, gender atypicality, and sexual orientation in Samoan males. Archives of Sexual Behavior, 46, 1375-1381.

Petterson, L.J., VanderLaan, D.P. & Vasey, P.L.
Sex, sexual orientation, gender atypicality, and traits of depression and anxiety in childhood and adulthood. Archives of Sexual Behavior, 46, 1383-1392.

Semenyna, S.W., VanderLaan, D.P. & Vasey, P.L.
Birth order and recalled gender nonconformity in Samoan men and fa'afafine. Developmental Psychobiology, 59: 338-347.

Gómez, F.R., Semenyna, S., Court, L. & Vasey, P.L.
Recalled childhood separation anxiety in Istmo Zapotec men, women, and muxe. Archives of Sexual Behavior, 46: 109-117.

Petterson, L.J, Wrightson, C. & Vasey, P.L.
A retrospective study of childhood gender-atypical behavior in Japanese androphilic males. Archives of Sexual Behavior, 46: 119-127.

Semenyna, S.W., Petterson, L.J., VanderLaan, D.P. & Vasey, P.L.
A comparison of the reproductive output among the relatives of Samoan androphilic fa'afafine and gynephilic men. Archives of Sexual Behavior, 46: 87-93.

VanderLaan, D.P., Petterson, L.J., & Vasey, P.L.
Elevated kin-directed altruism emerges in childhood and is linked to feminine gender expression in Samoan fa'afafine: A retrospective study. Archives of Sexual Behavior, 46: 95-108.

Vasey, P.L.
Homosexual Behavior. In: M. Bezanson et al. (eds), The International Encyclopedia of Primatology. NY: Wiley & Sons. (online)

Vasey, P.L. & VanderLaan, D.P.
The homosexual paradox---fa'afafine. In: Shackelford, T.K. & Weekes-Shackelford, V.A. (eds.), Encyclopedia of Evolutionary Psychological Science. NY: Springer. (online).

VanderLaan, D.P. & Vasey, P.L.
The homosexual paradox—kin selection hypothesis. In: Shackelford, T.K. & Weekes-Shackelford, V.A. (eds.), Encyclopedia of Evolutionary Psychological Science. NY: Springer.


2016

Gunst, N., Forteau, A.M., Philbert, S., Vasey, P.L., & Leca, J.-B.
Decline in population density and group size of mona monkeys in Grenada: Implications for the conservation of non-native primate species. Primate Conservation, 30: 7-13.

Semenyna, S. & Vasey, P.L.
The relationship between adult occupational preferences and childhood gender nonconformity among Samoan women, men, and fa'afafine. Human Nature, 27: 283-295.

Leca, J-B., Gunst, N., Pelletier, A., Vasey, P.L., Nahallage, C., Watanabe, K. &
Huffman, M.
A multidisciplinary view on cultural primatology: Behavioral innovations and traditions in Japanese macaques. Primates, 57(3): 333-338.

Li, F., Rendall, D., Vasey, P.L., Kinsman, M., Ward-Sutherland, A., Diano, G.
The development of sex/gender-specific /s/ and its relationship to gender identity in children and adolescents. Journal of Phonetics, 57: 59-70.

Bailey, M.J., Vasey, P.L., Diamond, L., Breedlove, M., Villain, E. &
Epprecht, M.
Sexual orientation, controversy and science. Psychological Science in the Public Interest, 17: 45-101.

MacFarlane, G.R. & Vasey, P.L.
Promiscuous primates engage in same-sex genital interactions. Behavioral Processes, 126: 21-26.

Vasey, P.L., VanderLaan, D.P., Hames, R. & Jaidee, A.
A problematic test of the kin selection hypothesis among the Urak-Lawoi of Ko Lipeh, Thailand: Commentary on Camperio Ciani, Battaglia, & Liotta (2015). Journal of Sex Research, 53: 149-152.

Petterson, L.J., Dixson, B.J., Little, A.C., & Vasey, P.L.
Reconsidering male bisexuality: Sexual activity role and sexual attraction in Samoan men who engage in sexual interactions with fa'afafine. Psychology of Sexual Orientation and Gender Diversity, 3: 11-26.

VanderLaan, D.P., Petterson, L.J. & Vasey, P.L.
Femininity and kin-directed altruism in homosexual men: A test of an evolutionary developmental model. Archives of Sexual Behavior, 45: 619-633.

In The Media

Print (Selected examples):

The Atlantic (2016)

The Economist (2004)

Natural Geographic Magazine (2017)

New York Times (2010)

O, The Oprah Magazine (2004, 2010).

Playboy (2017)

TIME (2013, 2016)



Television (Selected):

BBC Channel 4 (2019)

Discovery Channel (2000, 2003, 2005)

National Geographic (2004, 2017)

The Nature of Things (CBC) (2013)

Swedish Public Television (2003)



Radio (Selected):

Canadian Broadcasting Corporation (CBC) Radio (2008, 2012, 2013, 2014)

USA National Public Radio (2010)

Radio Netherlands (2003)

Research Interests

sexual orientation, gender diversity, sex differences, cross-cultural research, cross-species research, evolution

Current Research and Creative Activity

Title	Location	Grant Information	Principal Investigator	Co Researchers
Identification of genes influencing male sexual orientation on a Polynesian island	Samoa	Canadian Institute for Health Research, 2010-2011.	Paul L. Vasey, University of Lethbridge
The biopsychology of non-conceptive sex	Samoa, Japan, Canada	Natural Sciences and Engineering Research Council of Canada, 2010-2015.	Paul L. Vasey, University of Lethbridge
The Puzzle of Sexual Orientation: What is it and how does it work?	Canada	Social Sciences and Humanities Research Council of Canada Aid to Research Workshops and Conferences in Canada.	Paul L. Vasey & Martin Lalumière

Previous Research

Title	Grant Agency	Completion Date
The development and evolution of female homosexual behaviour in Japanese macaques	Fonds pour la Formation de Chercheurs et l'Aide à la Recherche Postdoctoral Fellowship	2000
The development and evolution of female homosexual behaviour in Japanese macaques	L.S.B. Leakey Foundation General Research Grant	2002
The development and evolution of female homosexual behaviour in Japanese macaques	Natural Scienes & Engineering Research Council of Canada (NSERC)	2005
The biopsychology of non-conceptive sex	Natural Sciences and Engineering Research Council of Canada	2005-2009
The neuroethology of female homosexual behavior in Japanese macaques	Natural Sciences and Engineering Research Council of Canada	2001-2004
Female-female mounting in Japanese macaques	L.S.B. Leakey Foundation General Research Grant
Female homosexual behaviour in Japnaese macaques	Fonds pour la Formation de Chercheurs et l'Aide à la Recherche Postdoctoral	1999-2001

Internet Links

The Kinsey Institute Interview Series: A Conversation with Dr. Paul Vasey