Males were the most eager to view sexually arousing images of the opposite sex, whereas females were more strongly motivated to view less sexual images of couples

Sex Differences in the Motivation for Viewing Sexually Arousing Images. Maiko Kobayashi, Koyo Nakamura & Katsumi Watanabe. Evolutionary Psychological Science, Feb 27 2021. https://rd.springer.com/article/10.1007/s40806-021-00276-y

Abstract: Sexual motivation strongly influences mate choice and dating behavior and can be triggered by merely viewing sexually arousing visual images, such as erotic pictures and movies. Previous studies suggested that men, more than women, tend to search for sexual cues that signal promiscuity in short-term mates. However, it remains to be tested whether sex differences in the motivation to view sexual cues can be observed by using robust and well-controlled behavioral measures. To this end, we employed a pay-per-view key-pressing task. Japanese self-identified heterosexual male and female participants viewed images of men, women, or couples with two levels of sexual arousal (sexual vs. less sexual). Participants could alter the viewing time of a presented image according to their willingness to keep viewing it. Male participants were the most eager to view sexually arousing images of the opposite sex, whereas female participants were more strongly motivated to view less sexual images of couples. Such sex differences may reflect differentiated reproductive strategies between men and women in terms of men’s motivation toward promiscuity and women’s motivation toward long-term relationships.

Discussion

The purpose of this study was to examine whether there are differences between men and women in terms of their motivation to view sexual images. Drawing on SST (Buss & Schmitt, 1993), we hypothesized that our self-identified heterosexual male and female participants would view the opposite-sex images longer than the same-sex images because opposite-sex images can evoke sexual arousal (Chivers & Bailey, 2005; Hahn et al., 2013), and that men would be more eager than women to view the highly sexual images because sexually explicit opposite-sex images suggest sexual accessibility (Buss & Schmitt, 1993). Our results indicate that the motivational salience of sexual images differed between male and female participants. Here, we summarize the main findings and interpret such differences in light of the SST (Buss & Schmitt, 1993).

First, as predicted, our male participants viewed the opposite sex images and couple images longer than the same sex images, irrespective of the sexual arousal of the images. These results confirm that heterosexual males are strongly motivated to view opposite sex images (Baumeister et al., 2001; Hamann et al., 2004). Furthermore, the number of key-presses by the male participants for the opposite sex images in the sexual condition was higher compared to that for the other image. Such prioritized motivational responses to the opposite sex images were also evident in likability and sexual arousal ratings. In the less sexual condition of the opposite-sex images, there were no significant differences in the pay-per-view key pressing, but there were significant differences in subjective likeability and arousal ratings. This result was not reflected in the behavior of opposite sex images with less sexual condition, even though male participants reported higher levels of subjective sexual arousal and preference than female participants. This suggests that the pay-per-view responses reflect sexual motivation to view the images, not merely the subjective evaluations of them (Aharon et al., 2001). These observations of the male participants’ behavior are consistent with the behavioral predictions provided by the SST (i.e., prediction 6: cues to immediately available sex will be valued by men in short-term mates more than in long-term mates because they provide cues to sexual accessibility). Previous studies also suggest that men are likely to prefer visual sexual cues than women, and are thus eager to view nude images of women (Baumeister et al., 2001; Regnerus et al., 2016). Also, recent studies reveal that heterosexual men prefer to view opposite-sex images in both erotic and non-erotic contexts more than heterosexual women do (Lykins et al., 2006; Lykins et al., 2008; Rupp & Wallen, 2007). Taken together, these findings suggest that men tend to value cues to immediately available sex (e.g., promiscuity) in short-term mates (Buss & Schmitt, 1993), possibly leading to men’s greater attraction to sexually arousing visual images (Symons, 1979). Our results support these previous findings by using a behavioral measurement that reflects sexual motivation.

In contrast to the male participants, the female participants displayed different patterns of pay-per-view responses depending on the sexual arousal of the images. From the standpoint of mate choice, the female participants would have also viewed the male images longer than the female images (Chivers & Bailey, 2005; Hahn et al., 2013). However, the female participants in this experiment viewed the couple images longer than the other images, while they decreased the viewing time for all types of images in the sexual condition. Female participants in this study were less responsive than male participants to opposite sex images in all pay-per view key-pressing, subjective likeability and arousal. Previous studies indicate that women react to men’s physical attractiveness as strongly as men react to women’s physical attractiveness (Hahn et al., 2013; Hamann et al., 2004; Wiederman & Dubois, 1998). This indicates that men and women are equally able to identify sexual cues from the opposite sex (Kowalski, 1993). It is noteworthy that many previous findings were based on participants from Western cultures; so, the inconsistency between previous findings and our results may be partially derived from cultural and social differences in sexual attitudes (Thomas et al., 2015). Our results that women decreased viewing time for both sexual and less sexual same sex images ostensibly seem to be inconsistent with some previous findings (e.g., Women react to men’s physical attractiveness as strongly as men react to women’s physical attractiveness (Hahn et al., 2013; Hamann et al., 2004; Wiederman & Dubois, 1998). One possible explanation for the inconsistent results can be provided by cultural differences in expression and social expectations of female sexuality. Indeed, Western women tend to explicitly report higher sexual desire, arousal, and pleasure when experiencing orgasm compared to East Asian women (Brotto et al., 2005; Cain et al., 2003). Also, East Asian women are likely to have automatic thoughts related to sexual guilt (e.g., “I am an immoral person for wanting sex,” or “It is wrong for a woman to initiate sexual activity?”), which may originate from implicit social expectations of female sexuality and thereby motivate them to avoid sexual scenarios they believe immoral (Woo et al., 2011). Although such cultural differences are also found in men, they are reflected in women more strongly (Abramson & Imai-Marquez, 1982). It would be interesting to address this question by conducting a cross-cultural study with East-Asian and Western populations.

Of particular interest is that our female participants viewed the couple images longer than the male and female images in the less sexual condition. Such patterns were also observed in the subjective likeability rating task but not in the subjective arousal task. These results are consistent with previous findings that women are highly motivated to view couple images depicting relationship contexts and emotional bonds (Laan et al., 1994; Carvalgho,  2013). According to the behavioral prediction of the sexual strategies theory, women place more emphasis on romantic relationships than men’s physical attractiveness (Rupp & Wallen, 2007). Indeed, Dewitte (2015) showed that women feel greater sexual desire when primed with visual cues conjuring up romantic relationships. Correspondingly, women experience more intense sexual arousal when viewing pornography with romantic elements (e.g., glancing at each other, kissing, or marriage) than pornography with actual sexual intercourse (Laan et al., 1994). In our study, the female participants displayed prolonged viewing of less sexual couple images compared to the highly sexual couple images. The less sexual couple images often include romantic elements as described above. The female preference for romantic or relational elements likely derives from psychological adaptations for long-term relationship and pair-bonding signals (Buss & Schmitt, 1993; Chivers & Timmers, 2012). Long-term relationships are more advantageous for women than for men (Trivers, 1972), because women tend to be the more heavily investing sex (e.g., fertilization, gestation, placentation, and maternal care). Thus, women’s strong preference for long-term mating cues might reflect the motivation to secure the quantity and quality of external resources for themselves and their offspring from men (Buss & Schmitt, 1993). At the same time, our female participants made key-press responses to reduce the viewing time for images with high sexual arousal (sexual condition), regardless of the image category. This response pattern may be related to an adaptive behavior such as preventing the initiation of sexual intercourse after only brief intervals of time (Buss & Schmitt, 1993) and/or women’s sexual attitudes are influenced by societal norms that place them in a dilemma regarding sexuality, such that female sexuality has historically been suppressed and deemed as immoral (Lemer et al., 2013).

The present study has been based on the sexual strategies theory and has discussed considerations related to reproductive success, such as opposite-sex and couple images, but it is necessary to discuss the results for same-sex sexual images, which are not thought to contribute to reproduction according to the sexual strategies theories. Our female participants were more motivated, more preferred, and more aroused by the same sex images with less sexual condition than male participants. This result may be due to a greater intra-individual variation in female preferences, behavior, attitudes, and responsiveness to cultural influences drives. Greater flexibility in female sexual preferences may also be reflected in a less specific pattern of sexual arousal (Baumeister et al., 2001; Chivers et al., 2004). These response characteristics to same-sex sexual stimuli are important in examining various genders, including LGBT, and can provide valuable insights for discussions that go beyond sexual strategies theory.

Limitations and Directions for Future Research

While the findings of the current study are novel, there exist several limitations to be considered. As mentioned in the introduction, sexual arousal is a multifaceted concept that includes physical, subjective, emotional, and behavioral aspects (Bancroft et al., 2009). Among them, this study focused on the motivation to view sexual images in an experimental setting as indexed by the pay-per-view key-pressing responses. It is important to keep in mind that the pay-per-view responses are not the direct measures of actual sexual behaviors and physiological arousal. Sex differences in psychological reactions to sexual cues await further validation with physiological and subjective measurements. In addition, the visual stimuli we used were limited to images from Western models, while the participants in this study were Japanese. Some studies demonstrate that people are susceptible to recognition errors or biased emotional evaluation when target images are from an unfamiliar group rather than their own group (e.g., other-race-effect; Feng et al., 2012; Herrmann et al., 2007; Hugenberg et al., 2010). Although we confirmed in the preliminary experiment that Japanese viewers were able to evaluate sexual arousal consistently, it may be more appropriate to use sexually arousing images from the same cultural group. However, to the best of our knowledge, the image database including a Japanese erotic category is not publicly available yet. Our findings await validation from future studies by using images from the same and different groups. Lastly, we could not rule out the possibility that unidentified factors other than sexual arousal and the image categories of our image stimuli affected the viewing time in the pay-per-view task because of the lack of experimental control for the components constituting each image, such as the presence of faces, the number of persons, and so on. More detailed analysis is needed for a deeper understanding of what triggers the sex differences in the motivation to view sexual images.