**5. Adolescence**

There is other evidence to suggest that facial representations become more differentiated with age and affect preferences for averageness. Like the infant studies described earlier [30, 31], 5-year-olds, 9-year olds, and adults viewed pairs of faces that included two images of the same person—one image was morphed to be 50% closer to the group average (*more average* face) and the other was morphed to be 50% away from the group average (*less average* face) [58]. Participants indicated which face was more attractive. Unlike the infants, all three age groups showed a significant preference for *more average* faces, with the effect becoming stronger with age—adults more often chose *more average* faces than 9-year-olds and 9-year-olds more often chose *more average* faces than 5-year-olds. These findings support the idea of development and refinement of separate representations for male and female faces with age. Results also revealed that participants more often selected *more average* adult female faces than *more average* adult male faces, but that target sex difference was not consistently observed for 5-year-old and 9-year-old target faces [58]. This discrepancy might have occurred because children are in the process of forming more distinct representations for female and male faces and for adult and child faces [56, 57]. Given early predominant experience with adult females for most children [18–22], the adult female face category average should be more established than the adult male face category average or child categories and thus most greatly influence averageness

The developmental change in children's facial representations might also explain why only 8-year-olds, and not 5- to 7-year-olds, could accurately judge the physical attractiveness of older aged, post-pubertal males (i.e., 17-year-olds) [59]. It might be necessary for children to develop separate facial representations for pre-pubertal and post-pubertal males for them to more accurately judge older males' attractiveness. Pre-pubertal girls' and boys' faces are relatively similar looking to one another and are more similar looking to adult female faces than adult male faces. Post-pubertal males' faces, however, are quite differentiated from adult females' faces due to males' development of secondary sex characteristics [60]. Subsequently, it is more difficult for both 7- to 10-year-olds and adults to classify the sex of pre-pubertal faces compared with adult faces, especially when only internal facial features are available to make the judgement [61]. Starting around 8 years of age, therefore, children's more differentiated facial representations should start to more strongly impact their attractiveness judgments and biases for male targets. Given the greater saliency of females than males' attractiveness in the years prior, however, and the likelihood that separate representations for female faces are established earlier in development than separate representations for male faces, attractiveness might continue to have a stronger influence on perceptions and processing when observing female relative to male targets. For example, 12-year-olds and undergraduate students rated the musical performance of 6th grade pianists more positively when they also perceived that

person as attractive, but this effect was limited to female pianists only [62].

Perhaps not surprisingly, girls seem to understand the concept of attractiveness and its importance for their gender earlier in development than boys. For example, when 3- to 6.5-year-olds were asked what it means to be pretty or cute, the oldest aged girls provided the most detailed descriptions [48]. Similarly, when 3- to 11-year-olds were asked to sort and label pictures of peers based on attractiveness, girls were significantly more accurate at this task than boys [63]. In the study where children spontaneously produced information about girls and boys, the

preferences for adult female faces.

134 Perception of Beauty

Adolescence may be a time of significant development in terms of attractiveness judgments. As adolescents reach puberty, males' and females' faces become more divergent as they increase in sexual dimorphism—male faces become more masculine and female faces become more feminine [65]. Puberty leads to heterosexuals' increased interest in opposite-sex interactions and dating [66, 67]. Thus, much of the literature regarding attractiveness preferences in adolescence focuses on mating preferences. The emergence of mating choice motives may lead to increased attention to physical appearance. For example, both male and female 14- to 16-year-olds preferred attractive mates for casual sexual relationships [68].

In addition to these changes, adolescents' facial representations are becoming even more differentiated as reflected in continued improvements in face recognition and perception between early and late adolescence [69]. These changes also affect their attractiveness preferences. In studies examining 11- to 16-year-olds' preferences for certain characteristics of male and female faces, participants viewed face pairs consisting of the same face manipulated to be more or less average, symmetrical, or feminine [70, 71]. Manipulations involved morphing techniques like those used in the infant and child studies [30, 31, 58]. Both male and female adolescents showed a preference for faces that were manipulated to be more average, feminine, or symmetrical. Like the findings from middle childhood, the preference for averageness increased with age. Older aged adolescents (13 + years-old) showed a stronger preference for *more average* faces than the younger aged adolescents [70, 71], likely due to their having developed more differentiated summary representations for female and male faces. Thus, the transition from a singular representation of human faces (i.e., a representation that is weighted toward adult females and attractive) to more differentiated averaged representations of face categories based on gender, age, and other attributes is quite protracted and takes several years to develop. It is currently unclear when it becomes adult-like, but increased interactions with same- and other-sex peers during adolescence [66, 67] should facilitate the transition and cause similarity to a facial category average to become increasingly more important when making attractiveness judgments.

Interestingly, 11- to 16-year-olds also showed a preference for both female and male faces altered to be more feminine [70, 71]. An exception to this finding was that males who had completed pubertal development (as measured via underarm hair growth and voice change) preferred significantly fewer feminized male faces compared with pre-pubertal and midpubertal boys [71]. The general preference for feminized faces suggests that perhaps the early emerging positive biases associated with faces similar to a female-like facial representation continue to influence preferences in adolescence. For the post-pubertal males, experience with their own face and faces of other post-pubertal male peers should shape their representation for this face category and subsequently influences preferences [71].

There are other discrepancies in the literature regarding whether female adolescents prefer facial femininity or masculinity when judging males' attractiveness. For example, pre-pubescent females (11- to 14-year-olds) displayed significantly lower preferences for a masculinized than feminized version of a male face compared with mid- and post-pubescent females (15- to 25-year-olds [72]. It is possible that like the post-pubescent males in the other study [71], the post-pubescent females are developing a more masculine representation for male faces due to their greater experience with post-pubertal males at this age. Yet, discrepancies exist regarding female preferences for male facial masculinity or femininity in other studies as well [65], leading to suggestions that preferences for masculine or feminine male faces may be context-dependent [71, 73, 74]. For example, adolescent and adult females (aged 16–39) preferred masculine faces when they were considering a short-term relationship or were already in a relationship [73]. Females may prefer feminine male faces due to their cuing of prosocial and other desirable traits, such as warmth, honesty, and cooperativeness [75], but prefer masculine male faces for cues related to dominance and genetic quality [76, 77]. In line with this theory, when women saw pairs of male faces and were asked to select which face better represented different traits, they rated masculine male faces as more dominant but less warm and less faithful than feminine male faces [78].

It is possible that discrepancies in preferences for masculine and feminine male faces stem from conflicting developmental processes. Recall that masculinity was a more salient cue than attractiveness when infants and children categorized male faces. If 12-month-olds categorized low masculine male faces due to an overgeneralization of their ability to categorize female faces [39], it might serve as a precursor to linking feminine attributes to low masculine males. Similarly, 4- to 5-year-olds' slower reaction time and higher error rate when classifying the sex of low than high masculine male faces [43] might persist throughout development. Indeed, adults' initial reaction upon viewing a low masculine male and selecting a genderrelated attribute was to initially move their computer mouse toward the side of the screen with a feminine attribute (e.g., caring) before moving it toward the side of the screen with a masculine attribute (e.g., aggressive) [79]. Prosocial qualities often associated with women, therefore, seem to be instinctively overgeneralized to low masculine male faces. During adolescence, such qualities should be preferred in certain contexts more than others. More research is needed, however, to understand whether and how early emerging attention to facial masculinity interacts with the developmental issues adolescent females encounter to influence their preference for low or high masculine males.

What is clear during adolescence is that attractiveness continues to more significantly impact female than male targets. Thirteen- to 19-year-old males rated young adult females who were high attractive more positively than low attractive females, whereas 13- to 19-year-old females did not significantly differ in their evaluations of high versus low attractive young adult males [80]. The emergence of mating motives in adolescence, in combination with early experiences that bias preferences toward attractive female faces, might account for males' strong attractiveness biases for female targets [81].

Male and female adolescents' self-appraisals and ideas about attractiveness also support the conclusion that males may place more emphasis on females' attractiveness than females place on males' attractiveness. Adolescents aged 13–15 answered questionnaires relating to their self-perceived attractiveness and indicated their level of agreement with statements suggesting attractive people display positive and prosocial traits (e.g., friendly and sociable) and unattractive people display negative traits (e.g., unreliable). Adolescent males reported higher self-ratings of how good looking and physically appealing they were compared with adolescent females, and showed higher agreement with attractiveness stereotypes than did females [82]. Because female adolescents rated themselves as less attractive and appealing than male adolescents, it suggests they internalized the importance of female attractiveness and were subsequently more critical of themselves. These self-ratings were related to attractiveness biases, suggesting that females may be less inclined to stereotype others based on attractiveness during adolescence compared with earlier in development [46].

In sum, a variety of developmental changes occur during adolescence that motivate and increase teens' attention toward and interactions with other-sex peers. These social experiences likely facilitate further differentiation of their facial representations. Moreover, early emerging preferences for attractive females align with heterosexual males' increased interest in females, which might augment the importance of attractiveness when adolescent males judge females. In contrast, although heterosexual females also prefer attractive partners, their bias for males' attractiveness might not become as strong because it does not align as well with early emerging preferences for attractive females. Male facial masculinity or femininity, however, should indicate similarity to a female face and might subsequently advertise traits that females consider attractive within different contexts. Longitudinal research is needed, however, to understand if and how early categorization of and preferences for certain facial cues in female and male faces contribute to later development of adolescents' attractiveness preferences.
