Abstract: The human body conveys socially relevant information, including a person’s gender. Several studies have shown that both shape and motion inform gender judgments of bodies. However, while body shape seems to influence more the judgment of female bodies, body motion seems to play a major role in the judgments of male bodies. Yet, the interdependence of morphologic and dynamic cues in shaping gender judgment and attractiveness evaluation in body perception is still unclear. In two experiments, we investigated how variations of implied motion and shape interact in perceptual and affective judgments of female and male bodies. In Experiment 1, participants were asked to provide ratings for masculinity and femininity of virtual renderings of human bodies with variable gender-typing features and implied motion. We found evidence of a tendency to perceive bodies in static poses as more feminine and bodies in dynamic poses as more masculine. In Experiment 2, participants rated the same pictures for dynamism and pleasantness. We found that male bodies were judged more dynamic than female bodies with the same pose. Also, female bodies were liked more in static than in dynamic poses. A mediation analysis allowed us to further shed light on the relationship between gender-typing features and motion, suggesting that the less is the movement conveyed by a female body, the greater is an observer’s sensitivity to its femininity, and this leads to a more positive evaluation of its pleasantness. Our findings hint to an association between stillness and femininity in body perception, which can stem from either the evolutionary meaning of sexual selection and/or the influence of cultural norms.
General Discussion
The present study aimed to investigate how the manipulation of gender-specific morphological features and implied motion of a body interact in its judgments. To this end, we asked participants to rate the masculinity and femininity (Experiment 1) or the dynamism and pleasantness (Experiment 2) of a series of pictures depicting male and female bodies expressing different amounts of gender-typing features (60% vs. 90% typicality) and displayed in static or dynamic postures. As expected, participants assigned higher value of masculinity and femininity to more gender-typical male and female bodies, respectively. However, the most interesting finding was that also implied motion influenced the gender judgment of body figures, at least when they were displayed with less gender-typing features (i.e., 60% typicality). Indeed, participants tended to perceive low-typical female bodies as more feminine when displayed in static than dynamic poses and to perceive low-typical male bodies as more masculine in dynamic than static poses. Crucially, however, not only implied motion influenced the perception of the gender-typing features of a body figure, but also gender typicality influenced the perception of motion conveyed by a body posture. Indeed, we found that models with typical female-typing features were evaluated as less dynamic than models with typical male-typing features, even when they displayed the same pose. This pattern of results suggests that gender-typing morphological cues and implied motion interact in shaping the perception of body gender. When morphological cues are not clear, the perception of static or dynamic postures pushes gender perception toward a female or male body, respectively. In a similar vein, when the motion conveyed by a body is fuzzy (e.g., implied motion in body pictures), the perception of female- or male-typing features pushes motion perception toward stillness or dynamism, respectively.
Importantly, we also found, at both subject- and item-level analyses, that the association between stillness and femininity influenced the aesthetic appreciation of a body. Indeed, bodies with more gender-typing features (i.e., 90% typicality) were liked more than less-typical bodies (60% typicality). This is in line with the notion that the stereotypical representation of the body according to its gender has implications for its aesthetic appreciation (McCreary et al., 2005), reflecting a correlation between gender-typing features and the impression of a good-looking body (Johnstone, 1994; Grammer et al., 2003; Singh and Singh, 2011). However, we also found that, within female figures, the models in static poses were evaluated as more pleasant than those in dynamic poses. This may seem in contrast with studies showing that more dynamic dance poses are liked more (Calvo-Merino et al., 2008; Cross and Ticini, 2012; Kirsch et al., 2016) and that implied motion enhances the aesthetic appreciation of human bodies (Cazzato et al., 2012), in terms of either attribution of intrinsic perceptual properties to the stimulus (i.e., beauty) or observer’s attitude to it (i.e., liking or attractiveness). However, albeit gender-typical features were less salient in these previous studies as compared to our study, implied motion was found to be a better predictor of the aesthetic appreciation of male than female bodies (Cazzato et al., 2012). In addition, the different impact of static and dynamic stimuli in the judgment of female physical attractiveness has already been reported in adult actresses, showing that more feminine WHRs and larger breasts are considered desirable traits in static photographs whereas more androgynous body shapes are considered appropriate in stars that perform in movies (Voracek and Fisher, 2006). Here we found that static postures increased the aesthetic appreciation of female bodies. This effect could be due to a direct negative effect of implied motion on the appreciation of female attractiveness or be indirectly mediated by a masking of female-typical physical traits. However, the item mediation analysis allowed us to better delineate the relationship between femininity perception, stillness and aesthetic appreciation. In particular, we tested two models, based on the hypothesis that either stillness increased the perceived femininity of a female body and thus increased its pleasantness (Model A) or that femininity reduced the implied motion of a female body and thus reduced its pleasantness (Model B). The results provided evidence in favor of the first model, since perception of femininity was a key mediator of the negative relation between implied motion and liking. In other words, the effect of implied motion on the liking judgments of female bodies was better explained by an indirect effect mediated by femininity than by a direct effect of implied motion on liking. This supports the claim that stillness increased the aesthetic appreciation of a female body at least partially because it increased its gender typicality, likely facilitating the perception of feminine-typing features. In sum, our data suggest that femininity and stillness, on one hand, and masculinity and dynamism, on the other hand, are associated features in body representation, confirming clues from both sexual-selection and socio-cultural frameworks.
In a sexual-selection evolutionist framework, perceiving a static female body vs. a dynamic male body may boost the salience of gender-typing physical traits, such as WHR for women and muscularity for men. Numerous studies, indeed, have shown that a female body is strongly defined by the WHR, since it appears to be related to objective gender-specific qualities such as the levels of sex hormones (e.g., estradiol; De Ridder et al., 1990; Mondragón-Ceballos et al., 2015), the accessibility to fat resources suitable for fetal neurodevelopment (Lassek and Gaulin, 2008), and the more general capacity to sustain pregnancy (Singh, 1993). Obviously, WHR might only serve as a proxy for covariating bodily traits that shape the entire body phenotype and co-determine the judgment of body attractiveness (Brooks et al., 2015). Certainly, being able to select these qualities on the basis of visual cues increases the reproductive success of the species and, in this respect, the body shape of a woman could be considered as the best way to rapidly infer her femininity, meant as a set of biologically determined attributes. Since WHR is based on the computation of the waist and hip proportions, it is plausible that movements may affect its estimation altering shape and size perception. A body in motion, indeed, can provide misleading information about shape, for instance by producing overlaps of body parts (i.e., arms that cover hips while running). As shown in a recent eye-tracking study (Pazhoohi et al., 2020), WHR is widely view-dependent and movement pattern can cause variation in WHR detection, even if body proportions remain constant. On this view, dynamism may hinder the expression of the femininity of a woman by obscuring her salient shapes as compared to when staying in canonical static poses.
Conversely, as in many animal species, humans show sex differences in body composition and the amount of muscle mass appears to be greater in men than in women (Wells, 2007). Performing actions may accentuate the perception of body muscularity, thus biasing gender perception toward masculinity. Furthermore, male individuals seem to tend to disclose their masculinity right through movements (Darwin, 1871), as demonstrated by males of some species which use dance as a signal of neuromuscular condition (Maynard Smith, 1956) or flight ability (Williams, 2001). In humans, for example, it has been shown that men’s bodily symmetry, a measure that reflects the developmental stability of an organism (Moller and Swaddle, 1997; Polak, 2003) and preservation from morbidity and mortality (Stevenson, 2000), strongly correlates with their dance ability (Brown et al., 2005) and running performance (Manning and Pickup, 1998). This suggests that movements, rather than shape, may be a better predictor of men’s functional effectiveness.
As a legacy of sexual selection, the stereotypical association between femininity/stillness and masculinity/dynamism is reflected in socio-cultural norms, grounded on how people think men and women should differ. A domain in which this distinction is quite tangible is represented by sports context. Indeed, studies have suggested that, in most of Western countries, girls and women are less encouraged to participate in sports than boys and men (Eccles and Harold, 1991; Hartmann-Tews and Pfister, 2003) and, even in physical activities where women are predominant, such as performing arts (i.e., ballet), performance seems to be judged more on the basis of aesthetic features than body capability (Klomsten et al., 2005). Nevertheless, media images in sports endorses the stereotyped view of men’s and women’s bodies, emphasizing strength and physical abilities in the case of male athletes but featuring female performers in terms of a sexualized body (Von Der Lippe, 2002). This is in line with the present finding that perception of femininity appears to be intensified by a static body pose. In this regard, studies about “woman objectification,” which refers to the tendency to perceive a woman worth in light of her body appearance and sexual function, have demonstrated that the identification of the female body as an object available for satisfying the needs of men may diminish her attribution of agency (Cikara et al., 2011) and, consequently, underline her passive condition. Interestingly, recent researches have shown that images of female bodies are processed as a recollection of body parts rather than a whole figure (Bernard et al., 2012, 2015), a fragmentary process that is generally observed in the recognition of objects; notably, this pattern of visual perception occurs independently from the gender of the observer, demonstrating that such objectification of the female body involves women themselves. Thus, the well-proved association between femininity and object-related features could easily explain why static postures make bodies to appear more feminine. At the same time, men are encouraged to display their sex-typing features in keeping with contemporary masculine norms, which consider increased muscle mass as more masculine (Mishkind et al., 1986; McCreary et al., 2005). This may explain why men tend to express their gendered body through exercising and practicing physical activity. Accordingly, a study aimed at exploring the association between levels of exercise and patterns of masculinity in men undergoing androgen deprivation therapy has recently revealed that men who are aerobically active have higher levels of self-reported masculinity than those who are inactive (Langelier et al., 2018), highlighting the intersection of masculinity and physical activity. Further, women also seem to judge masculinity through body movements, since they assess a man’s physical strength and attractiveness on the basis of his gait (Fink et al., 2016).
The conclusions that can be drawn from this study need to be weighted in the light of important limitations. First of all, we investigated the effects of dynamic cues in body perception by using static pictures of bodies with implied motion. This allowed controlling for the amount of body views offered in videos of a moving or still person, but obviously limits the salience and naturalness of body movements. Nevertheless, there is evidence for common neurocognitive representation of actual and implied body movements (Urgesi et al., 2006; Cazzato et al., 2014, 2016). Furthermore, the limited sample size prevented us from examining differences between male and female observers and to generally explore the role of individual differences in body-related processes on the association between stillness, femininity, and aesthetic appreciation of bodies. However, in keeping with previous findings (Bernard et al., 2012, 2015), our analyses showed overlapping pattern of results in male and female participants, at least in Experiment 1 where the effects of implied motion on masculinity/femininity perception were explored. Further studies with larger sample are required to appropriately test for gender effects in body perception. Furthermore, we found overlapping results not only when data were treated at the subject level, thus aiming at generalizing at wider population of male and female observers, but also at the item level, thus aiming at generalizing the results at a wider population of male and female bodies. The use of only a limited number of variations in gender typicality (i.e., 60% vs. 90%) prevents us from describing the effect of implied motion on female and male bodies along the continuous nature of gender typicality. Future studies, thus, need to test a larger sample and use different types of stimuli (e.g., videos of real rather than computer-generated bodies in movements) with greater variations of gender typicality and greater ecological validity in order to shed light on whether the association between stillness and femininity concerns mostly perceptive mechanisms or the stereotypical meaning assigned to men and women.