Masculine male facial characteristics (e.g., a pronounced brow and large jaw) are positively related to the circulating testosterone levels (Roney et al., 2006) and they may be regarded as a cue to good health (Gangestad and Simpson, 2000; Rhodes et al., 2003; Thornhill and Gangestad, 2006). Various factors contribute to individual differences in male facial masculinity preference in women, including relationship status (Sacco et al., 2012), self-reported attractiveness (Little and Mannion, 2006), sexual desire (Jones et al., 2011), sociosexuality (Glassenberg et al., 2010; Stower et al., 2019), and menstrual cycle (Penton-Voak et al., 1999; Johnston et al., 2001).

In general, gay and bisexual men prefer masculinized faces over feminized faces (Glassenberg et al., 2010; Zheng et al., 2013; Zheng and Zheng, 2015). However, some studies found no overriding preference among homosexual males for either masculine or feminine facial features (Valentová et al., 2013; Welling et al., 2013). There are also extensive individual differences in facial masculinity preference in gay and bisexual men for some variables, including sex role identity (i.e., tops, versatiles, and bottoms; Zheng et al., 2013), relationship status (Zheng, 2019), sexism (Zheng and Zheng, 2015), and pathogen disgust (Zheng et al., 2016).

Previous empirical evidence indicates homogamy in partner preference in gay men. Gay men prefer potential partners who are similar to themselves in personality (Štěrbová et al., 2017), height (Valentova et al., 2014, 2016), and beardedness (Valentova et al., 2017). Gay men prefer masculine men, and preference for masculinity may be related to the participants’ own levels of masculinity (Bailey et al., 1997). Gay men with positive attitudes toward masculine gay men preferred masculine male faces, voices, bodies, and personality traits (Zheng and Zheng, 2016). Moreover, homogamy in masculinity-femininity is positively linked to relationship quality in gay male couples (Bártová et al., 2017). Overall, previous studies indicated that gay men’s self-perceived masculinity and masculinity norms were related to masculinity preference in partner choice.

It is possible that gay men’s masculinity in the cognitive domain would be related to facial masculinity preference, based on the theory of homogamy. Mental rotation ability has been found to be related to masculine traits, such as systemizing (Cook and Saucier, 2010; Zheng and Zheng, 2017). In general, men significantly outperform women on tests of mental rotation ability (e.g., Voyer et al., 1995; Peters et al., 2007). Therefore, mental rotation ability is a masculine cognitive capacity and may be related to facial masculinity preference in gay men.

Mental rotation ability has been found to be highly related to face processing (e.g., Lewis, 2001; Stevenage and Osborne, 2006). The majority of previous studies manipulated the degree of facial masculinization and feminization based on the same original face (Rowland and Perrett, 1995; Penton-Voak et al., 1999). There were only minor differences between masculinized and feminized faces. Face processing-related ability might be helpful for individuals to determine their preferred facial features; if one could not detect the tiny differences between masculinized and feminized faces, on the other hand, this process would be difficult. If mental rotation ability is related to male facial masculinity preference via face processing ability, this effect would be true for both gay men and heterosexual women. Thus, I also assessed the relationship between mental rotation and preference for male facial masculinity in heterosexual women to test this hypothesis.

In addition, previous studies indicated that intrasexually competitive individuals similarly indicate heightened preferences toward good gene cues in same-sex faces (e.g., Sacco et al., 2009; Brown and Sacco, 2017). Gay men could view masculine men as competition as much as prospective mates. Therefore, it is possible that gay men with high mental rotation ability would prefer masculine faces due to the potential competition posed by masculine faces. To test this hypothesis, I also assessed the relationship between mental rotation and preference for male facial masculinity in heterosexual men. If competition contributes to facial masculinity preference, both gay and heterosexual men would show a similar pattern.

Overall, this study examined the association between mental rotation ability and facial masculinity preference in gay/bisexual men and heterosexuals in China. I hypothesized that gay and bisexual men with high mental rotation ability would prefer more masculine faces, based on the theory of homogamy. I also examined this association in heterosexual women to test the potential explanation of face processing ability. In addition, this association was also examined in heterosexual men to test whether this association was based on intrasexual competition rather than homogamy.

I conducted analyses of variance to examine group differences (heterosexual men, heterosexual women, gay men, and bisexual men) in the mental rotation ability and facial masculinity preference. There were significant differences in the mental rotation ability among groups, F(3, 809) = 17.9, p < 0.001, partial η² = 0.062. Bonferroni post hoc test revealed that heterosexual women (M = 7.94, SD = 2.14) scored lower on mental rotation task than heterosexual men (M = 8.80, SD = 2.23, d = 0.4, p < 0.001); bisexual men (M = 9.22, SD = 1.73, d = 0.63, p < 0.001); and gay men (M = 9.09, SD = 1.94, d = 0.57, p < 0.001). There were no significant differences among other groups. There were also significant differences in facial masculinity preference among groups, F(3, 809) = 7.72, p < 0.001, partial η² = 0.028. Bonferroni post hoc test revealed that gay men (M = 0.518, SD = 0.238) and bisexual men (M = 0.507, SD = 0.211) preferred more masculinized faces than heterosexual women (M = 0.427, SD = 0.222, d = 0.39/0.37, p < 0.001, d = 0.37, p = 0.017).

The association between the mental rotation ability and facial masculinity preference was significant for both the gay (r = 0.11, p = 0.045) and bisexual men (r = 0.22, p = 0.026) controlling for age, education, and occupation. There were no significant correlations between the mental rotation ability and facial masculinity preference in both heterosexual men (r = −0.054, p = 0.542) and women (r = 0.061, p = 0.342).

This study examined the association between the mental rotation ability and facial masculinity preference of gay and bisexual men. The results revealed that there was a significant association between mental rotation ability and facial masculinity preference in both gay and bisexual men, but not in heterosexual men or women.

There were significant gender differences in mental rotation ability, which is consistent with previous findings in western cultures (e.g., Voyer et al., 1995; Peters et al., 2007). However, there was no significant difference in mental rotation ability between heterosexual and homosexual men. Previous research has shown mixed findings with regard to sexual orientation differences in mental rotation ability. Some studies have found that heterosexual men outperform homosexual men in mental rotation ability (e.g., Rahman and Wilson, 2003; Maylor et al., 2007). Other research has shown no significant differences in mental rotation ability between heterosexual and homosexual men (e.g., Gladue et al., 1990). As for the facial masculinity preference, heterosexual women typically preferred more feminized male faces than did homosexual men. One recent study also indicated that women prefer feminized male faces in China (Liu and Wu, 2016).

The current findings indicated the association between mental rotation ability and facial masculinity preference. This association may be attributed to homogamy in partner preference in terms of masculinity in gay and bisexual men. Previous studies indicated that masculine gay and bisexual men tend to prefer masculine partners (Bailey et al., 1997; Zheng et al., 2013; Zheng and Zheng, 2015). Mental rotation ability is a masculine cognitive ability. Therefore, gay and bisexual men with high mental rotation ability would self-perceive more masculinity and prefer more masculine male faces. The current findings extend previous findings and indicate an association between masculine cognitive ability and facial masculinity preference, which was consistent with previous findings in heterosexual men that masculine cognitive style (i.e., systemizing) was related to facial masculinity preference (Smith et al., 2010). However, mental rotation was not associated with facial masculinity preference in heterosexual women. One previous study revealed no homogamy in facial masculinity-femininity in heterosexual couples (Burriss et al., 2011), which highlighted the homogamy theory in partner preference among gay and bisexual men.

If face processing ability could explain the association between mental rotation ability and facial masculinity preference, these associations should occur in both gay/bisexual men and heterosexual women. There was no significant association between mental rotation ability and facial masculinity preference in heterosexual women, which was consistent with a previous finding (Scarbrough and Johnston, 2005). This indicated that the association between mental rotation ability and facial masculinity preference could not be explained by face processing ability.

If gay and bisexual men’s preference for facial masculinity was based on intrasexual competition, mental rotation ability would be associated with facial masculinity preference in both gay/bisexual men and heterosexual men. There was no significant association between mental rotation ability and facial masculinity preference in heterosexual men, which was consistent with a previous finding (Vonnahme, unpublished). This indicated that preference for facial masculinity in gay and bisexual men was not based on intrasexual competition.

Mental rotation task performance is correlated with prenatal testosterone levels (Grimshaw et al., 1995), and relates to the ratio of the lengths of the second and fourth digits of the hand (a marker of prenatal exposure to androgens), which may reflect fetal exposure to prenatal sex hormones in early gestation (Burton et al., 2005; Collaer et al., 2007; Peters et al., 2007). Previous studies revealed the potential influences of prenatal androgen exposure on preference for exaggerated sex-typical characteristics in heterosexual men and women (Vonnahme, unpublished; Scarbrough and Johnston, 2005; Kuna and Galbarczyk, 2018). However, some recent studies did not find an association between hormone levels and facial masculinity preference (e.g., Jones et al., 2018a,b). The current findings may indicate the potential effects of prenatal androgen exposure on facial masculinity preference in gay and bisexual men.

There were several limitations in this study. First, the mental rotation task was conducted on a website rather than in a controlled laboratory environment. The devices that the participants used to complete the task may have influenced their performance because the display of the stimuli would be slightly different on a smartphone screen and desktop monitor. Second, as the current sample was young, the conclusion of this study is restricted to young gay and bisexual men in China. Third, the association between mental rotation ability and facial masculinity in gay and bisexual men was weak. The association between masculine cognitive ability and facial masculinity preference in gay and bisexual men should be tested with other abilities. Finally, the gay/bisexual participants and heterosexual participants were not recruited at the same time. This could have led to history effects.

All datasets generated for this study are included in the article/supplementary material.

The studies involving human participants were reviewed and approved by the Academic Ethical Review Committee of Faculty of Psychology in Southwest University. Written informed consent from the participants was not required to participate in this study in accordance with the national legislation and the institutional requirements.

The author confirms being the sole contributor of this work and has approved it for publication.