A statistical model of facial attractiveness

Previous research has identified facial averageness and sexual dimorphism as important factors in facial attractiveness. The averageness and sexual dimorphism accounts provide important first steps in understanding what makes faces attractive, and should be valued for their parsimony. However, we show that they explain relatively little of the variance in facial attractiveness, particularly for male faces. As an alternative to these accounts, we built a regression model that defines attractiveness as a function of a face's position in a multidimensional face space. The model provides much more predictive power than the averageness and sexual dimorphism accounts and reveals previously unreported components of attractiveness. The model shows that averageness is attractive in some dimensions but not in others and resolves previous contradictory reports about the effects of sexual dimorphism on the attractiveness of male faces.     

Computational models of facial attractiveness judgments

We designed two computational models to replicate human facial attractiveness ratings. The primary model used partial least squares (PLS) to identify image factors associated with facial attractiveness from facial images and attractiveness ratings of those images. For comparison we also made a model similar to previous models of facial attractiveness, in that it used manually derived measurements between features as inputs, though we took the additional step of dimensionality reduction via principal component analysis (PCA) and weighting of PCA dimensions via a perceptron. Strikingly, both models produced estimates of facial attractiveness that were indistinguishable from human ratings. Because PLS extracts a small number of image factors from the facial images that covary with attractiveness ratings of the images, it is possible to determine the information used by the model. The image factors that the model discovered correspond to two of the main contemporary hypotheses of averageness judgments: facial attractiveness and sexual dimorphism. In contrast, facial symmetry was not important to the model, and an explicit feature-based measurement of symmetry was not correlated with human judgments of facial attractiveness. This provides novel evidence for the importance of averageness and sexual dimorphism, but not symmetry, in human judgments of facial attractiveness.     

The influence of facial attractiveness on imitation

People judge, evaluate, and treat attractive people better than moderately attractive or unattractive people [Langlois, J. H., Kalakanis, L., Rubenstein, A. J., Larson, A., Hallam, M., & Smoot, M. (2000). Maxims or myths of beauty? A meta-analytic and theoretical review. Psychological Bulletin, 126, 390–423]. The fact that individuals like attractive people combined with the finding that individuals imitate the ones they like, suggests that they may be more prone to imitate attractive people. The present research extends previous work on attractiveness and imitation by examining this hypothesis. Using a novel coloring procedure, we show that attractive females are imitated more than unattractive females (Experiment 1) and that attractive males are imitated more than unattractive males (Experiment 2). Importantly, this imitation occurs without any direct or anticipated contact with the target individual and without awareness of the influence of attractiveness on imitation behavior.     

When facial attractiveness is only skin deep

Whilst the relationship between aspects of facial shape and attractiveness has been extensively studied, few studies have investigated which characteristics of the surface of faces positively influence attractiveness judgments. As many researchers have proposed a link between attractiveness and traits that appear healthy, apparent health of facial skin might be a property of the surface of faces that positively influences attractiveness judgments. In experiment 1 we tested for a positive correlation between ratings of the apparent health of small skin patches (extracted from the left and right cheeks of digital face images) and ratings of the attractiveness of male faces. By using computer-graphics faces, in experiment 2 we aimed to establish if apparent health of skin influences male facial attractiveness independently of shape information. Results suggest that apparent health of facial skin is correlated both with ratings of male facial attractiveness (experiment 1) and with being a visual cue for judgments of the attractiveness of male faces (experiment 2). These findings underline the importance of controlling for the influence of visible skin condition in studies of facial attractiveness and are consistent with the proposal that attractive physical traits are those that positively influence others' perceptions of an individual's health.     

Effect of facial stimuli exposure time on evaluation of facial attractiveness

Facial attractiveness has advantages both socially and sexually, and the human brain has evolved to perceive specific facial characteristics as attractive. The current research examined the effect of facial stimuli exposure time on facial attractiveness evaluations. In Experiment 1, 86 students observed 44 facial stimuli in short and long amounts of time. To eliminate any influence of repeated stimuli on the second observations, Experiment 2 was performed on 84 participants who observed the facial stimuli in either short or long durations. Differences in both experiments were significant. These studies showed that exposure time has an influence on the evaluation of facial attractiveness. Participants who were exposed to facial stimuli for a short amount of time perceived greater facial attractiveness than when they were exposed for a longer time to the same stimuli. In other words, faces were more beautiful when they were observed in a short amount of time, and this effect occurred regardless of gender.     

Effects of the beholder's age on the perception of facial attractiveness

Children have been shown to prefer faces rated as highly attractive by adults over faces rated as quite unattractive. We investigated to what extent this agreement holds not only for the general direction of preferences but for preference strengths as well. In a choice experiment, we presented 40 nine-year-old girls and their mothers and 40 twelve-year-old girls and their mothers with pairs of women's and girls' faces and asked the subjects to pick the face that appeared prettier to them. Preference frequencies and simple attractiveness scales derived from these preference frequencies by fitting the Bradley-Terry-Luce rule (Luce, D. R. (1959). Individual choice behavior: a theoretical analysis. New York: Wiley) were compared across subject groups. For the women's faces, we found no difference in preferences between nine-year-olds, twelve-year-olds, and adults, neither in direction nor in strength. For the girls' faces, we also found no major differences in preference direction, however, we did find reliable differences in preference strengths. To a considerable part these differences were due to the fact that the children showed less pronounced preferences between face stimuli than the adults. These results suggest a role of developmental factors in the perception of facial attractiveness.     

Analyses of facial attractiveness on feminised and juvenilised faces

We conducted two experiments to investigate the psychological factors affecting the attractiveness of composite faces. Feminised or juvenilised Japanese faces were created by morphing between average male and female adult faces or between average male (female) adult and boy (girl) faces. In experiment 1, we asked the participants to rank the attractiveness of these faces. The results showed moderately juvenilised faces to be highly attractive. In experiment 2, we analysed the impressions the participants had of the composite faces by the semantic-differential method and determined the factors that largely affected attractiveness. On the basis of the factor scores, we plotted the faces in factor spaces and analysed the locations of attractive faces. We found that most of the attractive juvenilised faces involved impressions corresponding to an augmentation of femininity, characterised by the factors of 'elegance', 'mildness', and 'youthfulness', which the attractive faces potentially had.     

The influence of position and context on facial attractiveness

It has been shown that a person's position in a group influences how that person is evaluated, with people in the middle perceived as more important than people on the fringe of a group. Four experiments examined whether the position of a face, in a line of five faces, influenced facial attractiveness. The middle position influenced the perceived attractiveness of the target face but the direction of this effect depended on the attractiveness of the target and the surrounding faces. Attractive faces were perceived as less attractive when in the middle of unattractive faces, or faces of average attractiveness. Conversely, unattractive faces were perceived as more attractive when in the middle of other unattractive faces. These results have wide implications, suggesting that the more central a stimulus is in a context then the greater the influence of the context on the judgment of that stimulus.     

The role of holistic processing in judgments of facial attractiveness

Previous work has demonstrated that facial identity recognition, expression recognition, gender categorisation, and race categorisation rely on a holistic representation. Here we examine whether a holistic representation is also used for judgments of facial attractiveness. Like past studies, we used the composite paradigm to assess holistic processing (Young et al 1987, Perception 16 747-759). Experiment 1 showed that top halves of upright faces are judged to be more attractive when aligned with an attractive bottom half than when aligned with an unattractive bottom half. To assess whether this effect resulted from holistic processing or more general effects, we examined the impact of the attractive and unattractive bottom halves when upright halves were misaligned and when aligned and misaligned halves were presented upside-down. The bottom halves had no effect in either condition. These results demonstrate that the perceptual processes underlying upright facial-attractiveness judgments represent the face holistically. Our findings with attractiveness judgments and previous demonstrations involving other aspects of face processing suggest that a common holistic representation is used for most types of face processing.     

The role of facial attractiveness and facial masculinity/femininity in sex classification of faces

We tested whether adults (experiment 1) and 4 - 5-year-old children (experiment 2) identify the sex of highly attractive faces faster and more accurately than not very attractive faces in a reaction-time task. We also assessed whether facial masculinity/femininity facilitated identification of sex. Results showed that attractiveness facilitated adults' sex classification of both female and male faces and children's sex classification of female, but not male, faces. Moreover, attractiveness affected the speed and accuracy of sex classification independently of masculinity/femininity. High masculinity in male faces, but not high femininity in female faces, also facilitated sex classification for both adults and children. These findings provide important new data on how the facial cues of attractiveness and masculinity/femininity contribute to the task of sex classification and provide evidence for developmental differences in how adults and children use these cues. Additionally, these findings provide support for Langlois and Roggman's (1990 Psychological Science 1 115 121) averageness theory of attractiveness.     

Computer graphic studies of the role of facial similarity in judgements of attractiveness

Anecdotally, spouses are often said to resemble one another. This study investigates the effects of similarity between participants and stimuli on judgements of facial attractiveness: does “like prefer like”? Using computer graphic techniques, opposite sex facial stimuli were generated from subjects' photographs. Experiment 1 showed a correlation between attractiveness and similarity but the effect can be explained by the attractiveness of average faces. Beyond this, there was a trend for individual subjects to rate opposite sex images with a similar face shape to their own face as more attractive than other subjects. Experiment 2 allowed subjects to interactively manipulate an opposite sex facial image along a continuum from a self-similar shape, through an average face shape, to a face with opposite characteristics. No significant preferences for self-similar or opposite characteristics were found. Preferences for average faces are stronger than preferences for self-similar faces.     

Symmetry, averageness, and feature size in the facial attractiveness of women

Female facial attractiveness was investigated by comparing the ratings made by male judges with the metric characteristics of female faces. Three kinds of facial characteristics were considered: facial symmetry, averageness, and size of individual features. The results suggested that female face attractiveness is greater when the face is symmetrical, is close to the average, and has certain features (e.g., large eyes, prominent cheekbones, thick lips, thin eyebrows, and a small nose and chin). Nevertheless, the detrimental effect of asymmetry appears to result solely from the fact that an asymmetrical face is a face that deviates from the norm. In addition, a factor analysis indicated that averageness best accounts for female attractiveness, but certain specific features can also be enhancing.     

The two sides of beauty: Laterality and the duality of facial attractiveness

We hypothesized that facial attractiveness represents a dual judgment, a combination of reward-based, sexual processes, and aesthetic, cognitive processes. Herein we describe a study that demonstrates that sexual and nonsexual processes both contribute to attractiveness judgments and that these processes can be dissociated. Female participants rated the general attractiveness of faces presented in either their left or right visual field. In order to examine sexual and nonsexual components of these judgments, general attractiveness ratings were correlated with ratings of these same faces made by two independent groups of raters in two specific contexts, one sexual and one nonsexual. Based on an items analysis, partial correlation coefficients were computed for each individual and used as the dependent variable of interest in a 2 (laterality: right, left) by 2 (context: sexual, nonsexual) ANOVA. This analysis revealed an interaction such that faces rated in a sexual context better predicted attractiveness ratings of faces shown in the left than right visual field, whereas faces rated in a nonsexual context better predicted attractiveness of faces shown in the right than left visual field. This finding is consistent with the assertion that sexual and nonsexual preferences involve predominantly lateralized processing routes that independently contribute to what is perceived to be attractive.     

The effects of facial adiposity on attractiveness and perceived leadership ability

Facial attractiveness has a positive influence on electoral success both in experimental paradigms and in the real world. One parameter that influences facial attractiveness and social judgements is facial adiposity (a facial correlate to body mass index, BMI). Overweight people have high facial adiposity and are perceived to be less attractive and lower in leadership ability. Here, we used an interactive design in order to assess whether the most attractive level of facial adiposity is also perceived as most leader-like. We found that participants reduced facial adiposity more to maximize attractiveness than to maximize perceived leadership ability. These results indicate that facial appearance impacts leadership judgements beyond the effects of attractiveness. We suggest that the disparity between optimal facial adiposity in attractiveness and leadership judgements stems from social trends that have produced thin ideals for attractiveness, while leadership judgements are associated with perception of physical dominance.     

You must have been a beautiful baby: ratings of infant facial attractiveness fail to predict ratings of adult attractiveness

Facial attractiveness has been studied extensively, but little research has examined the stability of facial attractiveness of individuals across different stages of development. We conducted a study examining the relationship between facial attractiveness in infants (age 24 months and under) and the same individuals as young adults (age 16–18 years) using infant and adult photographs from high school yearbooks. Contrary to expectations, independent raters’ assessments of infant facial attractiveness did not correlate with adult facial attractiveness. These results are discussed in terms of the adaptive function of heightened attractiveness in infancy, which likely evolved to elicit and maintain parental care.     

Effects of facial attractiveness and gender on causal attributions of managerial performance

The present study examined the effect of facial attractiveness and gender on raters' evaluations of and explanations for managerial performance. Results showed attractiveness to be a potential liability for both males and females. Good performance of attractive females was more likely than that of others to be attributed to luck or bias, while that of attractive males was viewed as occurring with little effort. In addition, the poor performance of attractive individuals was blamed on lack of effort (females) or lack of ability (males). Implications of these findings are discussed.An earlier version of this paper was published in the 1986 Proceedings of the Southern Management Association.     

Intensity of smiling and attractiveness as facial signals of trustworthiness in women

Facial attractiveness is associated with a variety of positive social characteristics including trustworthiness. Variations in smiling, such as the appearance of the Duchenne marker and increased intensity of expression, have likewise been linked with positive judgments of trustworthiness. The study investigated the interaction of the effects of models' attractiveness and their smiling intensity on impressions of perceived trustworthiness. Participants rated the attractiveness and expressivity of neutral, low intensity, and high intensity smiling images of 45 women models. These images were also presented to a second group of participants who rated trustworthiness. Repeated measures analysis of covariance of the effects of attractiveness and manipulated smile intensity on trustworthiness indicated a main effect for smile intensity: increased smile intensity was associated with greater trustworthiness. Attractiveness also contributed to rated trustworthiness independently of smiling intensity. Results suggested there is an additional contribution of facial expression in creating social impressions of trustworthiness.     

Perceived health contributes to the attractiveness of facial symmetry, averageness, and sexual dimorphism

Symmetry, averageness, and sexual dimorphism (femininity in female faces, masculinity in male faces) are attractive in faces. Many have suggested that preferences for these traits may be adaptations for identifying healthy mates. If they are, then the traits should be honest indicators of health and their attractiveness should result from their healthy appearance. Much research has focused on whether these traits honestly signal health. Here we focused on whether the appeal of these traits results from their healthy appearance. Specifically, we tested whether the attractiveness of symmetry, averageness, and sexual dimorphism is reduced or eliminated when perceived health is controlled, in two large samples of Western faces and a large sample of Japanese faces. The appeal of symmetric faces was largely due to their healthy appearance, with most associations between symmetry and attractiveness eliminated when perceived health was controlled. A healthy appearance also contributed to the appeal of averageness and femininity in female faces and masculinity in male faces, although it did not fully explain their appeal. These results show that perceptions of attractiveness are sensitive to a healthy appearance, and are consistent with the hypothesis that preferences may be adaptations for mate choice.     

Effects of framed spectacles and contact lenses on self-ratings of facial attractiveness.

15 females with glasses tended to defend against relatively low self-perceptions of attractiveness by de-emphasizing the influence of their eyes on facial beauty.