Developmental changes in children's facial preferences

Facial averageness, symmetry, health, and femininity are positively associated with adults' judgements of attractiveness, but little is known about the age at which preferences for individual facial traits develop. We investigated preferences for these facial traits and global attractiveness in 4- to 17-year-olds (N = 346). All age groups showed preferences for globally attractive faces. Preferences for averageness, symmetry, and health did not emerge until middle childhood and experienced apparent disruption or stasis around age 10- to 14-years; femininity was not preferred until early adulthood, and this preference was seen only in girls. Children's pubertal development was not clearly related to any facial preferences, but the results are consistent with the suggestion that early adrenal hormone release may play an activating role in mate preferences, while other constraints may delay further increases in preferences during later puberty.     

Cultural differences in preferences for facial coloration

Effects of facial coloration on facial attractiveness judgments are hypothesized to be “universal” (i.e., similar across cultures). Cross-cultural similarity in facial color preferences is a critical piece of evidence for this hypothesis. However, only two studies have directly compared facial color preferences in two cultures. Both of those studies reported that White UK and Black African participants showed similar preferences for facial coloration. By contrast with the cross-cultural similarity reported in those studies, here we show cultural differences in the effects of facial coloration on Chinese and White UK participants' facial attractiveness judgments. While Chinese participants preferred faces with decreased yellowness to faces with increased yellowness, White UK participants preferred faces with increased yellowness to faces with decreased yellowness. Chinese participants also demonstrated weaker preferences for facial redness and stronger preferences for facial lightness than did White UK participants. These results suggest that preferences for facial coloration are not universal.     

Evidence for MHC-correlated perfume preferences in humans

Fragrances have been used since at least 5000 years ago andall traditional scents are found in modern perfumes. Althoughperfumes are obviously involved in sexual communication, thesignificance of great individual differences in preferencefor fragrances is an evolutionary puzzle. The major histocompatibilitycomplex (MHC) is a highly polymorphic and conserved set of genes that plays an important role in immune function in vertebrates.Both mice and humans have been shown to prefer the body odorof potential partners that have a dissimilar MHC genotype,which would result in heterozygous offspring. We tested whetherindividual preferences for perfume ingredients correlate witha person's MHC genotype. The human MHC is called HLA (human leukocyte antigen). A total of 137 male and female studentswho had been typed for their MHC (HLA-A, -B, -DR) scored 36scents in a first test for use on self ("Would you like tosmell like that yourself?") and a subset of 18 scents 2 yearslater either for use on self or for a potential partner ("Wouldyou like your partner to smell like that?"). An overall analysisshowed a significant correlation between the MHC and the scoringsof the scents "for self" in both tests. In a detailed analysiswe found a significant interaction of the two most common HLAswith the rating of the 36 scents in the first study as wellas with the 18 scents in the second study when evaluated forself. This result suggests that persons who share, for example,HLA-A2, have a similar preference for any of the perfume ingredients.The significant repeatability of these preferences in the two tests showed that the volunteers that had either HLA-A1 or HLA-A2were significantly consistent in their preferences for theperfume ingredients offered. Hardly any significant correlationbetween MHC genotype and ratings of the scents "for partner"were found. This agrees with the hypothesis that perfumes areselected "for self" to amplify in some way body odors thatreveal a person's immunogenetics.     

Taste-induced facial expressions in apes and humans

Different gustatory stimuli activate distinct, stereotyped motorbehaviors of the orofacial region. These serve as nonverbal communicational signs, indicative of both intensity and hedonics of the perceived sensation. The present study aims to compare these orofacial motor-coordinations of apes with those of perinatal human infants. A group of 27 infants, prior to their first feeding-experience, as well as a group of 14 apes were tested. Video-recorded documentation of stimulation and stimulus-dependent responses for both groups were evaluated in a blind-setting. Overall hedonic ratings and semiquantitative analysis of the motion-features composing the facial expressions served as critical measures. Results revealed a sizeable correlation between mean hedonic ratings ascribed to the different responses of neonates and of apes. The semiquantitative analysis shows that sweet-, water- and bitter-stimuli activate almost identical motion-features in the orofacial regions of both groups tested. Findings also correlate with those obtained in testing adolescent, adult and elderly human examinees.     

Negative frequency-dependent preferences and variation in male facial hair

Negative frequency-dependent sexual selection maintains striking polymorphisms in secondary sexual traits in several animal species. Here, we test whether frequency of beardedness modulates perceived attractiveness of men''s facial hair, a secondary sexual trait subject to considerable cultural variation. We first showed participants a suite of faces, within which we manipulated the frequency of beard thicknesses and then measured preferences for four standard levels of beardedness. Women and men judged heavy stubble and full beards more attractive when presented in treatments where beards were rare than when they were common, with intermediate preferences when intermediate frequencies of beardedness were presented. Likewise, clean-shaven faces were least attractive when clean-shaven faces were most common and more attractive when rare. This pattern in preferences is consistent with negative frequency-dependent selection.     

Social transmission of face preferences among humans

Previous studies demonstrating mate choice copying effects among females in non-human species have led many researchers to propose that social transmission of mate preferences may influence sexual selection for male traits. Although it has been suggested that social transmission may also influence mate preferences in humans, there is little empirical support for such effects. Here, we show that observing other women with smiling (i.e. positive) expressions looking at male faces increased women's preferences for those men to a greater extent than did observing women with neutral (i.e. relatively negative) expressions looking at male faces. By contrast, the reverse was true for male participants (i.e. observing women with neutral expressions looking at male faces increased male participant's preferences for those men to a greater extent than did observing women smiling at male faces). This latter finding suggests that within-sex competition promotes negative attitudes among men towards other men who are the target of positive social interest from women. Our findings demonstrate that social transmission of face preferences influences judgments of men's attractiveness, potentially demonstrating a mechanism for social transmission of mate preferences.     

Social learning of novel route preferences in adult humans

Non-human animals can acquire novel route preferences by following knowledgeable individuals. Such socially learned route preferences can be stably maintained over multiple transmission episodes, sometimes forming long-lived traditions. In humans, preferences for familiar routes or heavily used worn trails over unfamiliar ones have been described in various contexts. However, social learning of route preferences has not been experimentally demonstrated in humans. Here, we demonstrate that social learning and tradition influence route choice. We led adult male and female participants into a room by one of two routes. Participants followed the demonstrated route choices, and later remembered and preferred this choice even when determinably suboptimal (i.e. longer and not preferred by control participants) or when the choice was indicated as arbitrary (the demonstrator took one route to retrieve a poster that had ostensibly fallen). Moreover, route preferences were stably maintained over multiple transmission episodes. We suggest that simple social learning processes, often neglected in human and primate research, can result in long-lived route preferences that may influence a range of additional behaviour patterns.     

The influence of infant facial cues on adoption preferences

Trivers’s theory of parental investment suggests that adults should decide whether or not to invest in a given infant using a cost-benefit analysis. To make the best investment decision, adults should seek as much relevant information as possible. Infant facial cues may serve to provide information and evoke feelings of parental care in adults. Four specific infant facial cues were investigated: resemblance (as a proxy for kinship), health, happiness, and cuteness. It was predicted that these cues would influence feelings of parental care for both sexes, but that resemblance would be more important for men than women because of the importance of paternity uncertainty in the ancestral environment. Seventy-six men and 76 women participated in a hypothetical adoption task in which they made judgments of infant faces. Average zero-order, partial, and component score correlations all revealed that men placed primary emphasis on cues of resemblance, while women placed primary emphasis on cues of health and cuteness (cues of infant quality). The correlations also showed that men placed a significantly greater emphasis on cues of resemblance than did women. This research was supported by a Queen’s University Graduate Award (first author) and a Senior Research Fellowship from the Ontario Mental Health Foundation (second author). Anthony Volk is a Ph.D. candidate at Queen’s University, studying parental investment. Vernon L. Quinsey is a professor of psychology and psychiatry at Queen’s University. His research focuses on forensic and evolutionary psychology. An erratum to this article is available at .     

MHC-correlated odour preferences in humans and the use of oral contraceptives

Previous studies in animals and humans show that genes in the major histocompatibility complex (MHC) influence individual odours and that females often prefer odour of MHC-dissimilar males, perhaps to increase offspring heterozygosity or reduce inbreeding. Women using oral hormonal contraceptives have been reported to have the opposite preference, raising the possibility that oral contraceptives alter female preference towards MHC similarity, with possible fertility costs. Here we test directly whether contraceptive pill use alters odour preferences using a longitudinal design in which women were tested before and after initiating pill use; a control group of non-users were tested with a comparable interval between test sessions. In contrast to some previous studies, there was no significant difference in ratings between odours of MHC-dissimilar and MHC-similar men among women during the follicular cycle phase. However, single women preferred odours of MHC-similar men, while women in relationships preferred odours of MHC-dissimilar men, a result consistent with studies in other species, suggesting that paired females may seek to improve offspring quality through extra-pair partnerships. Across tests, we found a significant preference shift towards MHC similarity associated with pill use, which was not evident in the control group. If odour plays a role in human mate choice, our results suggest that contraceptive pill use could disrupt disassortative mate preferences.     

Genetic dissimilarity,genetic diversity,and mate preferences in humans

It is clear that genes at the major histocompatibility complex (MHC) are involved in mate preferences in a range of species, including humans. However, many questions remain regarding the MHC's exact influence on mate preference in humans. Some research suggests that genetic dissimilarity and individual genetic diversity (heterozygosity) at the MHC influence mate preferences, but the evidence is often inconsistent across studies. In addition, it is not known whether apparent preferences for MHC dissimilarity are specific to the MHC or reflect a more general preference for genome-wide dissimilarity, and whether MHC-related preferences are dependent on the context of mate choice (e.g., when choosing a short-term and long-term partner). Here, we investigated whether preferences for genetic dissimilarity are specific to the MHC and also whether preferences for genetic dissimilarity and diversity are context dependent. Genetic dissimilarity (number of alleles shared) influenced male, but not female, partner preferences, with males showing a preference for the faces of MHC-dissimilar females in both mating contexts. Genetic diversity [heterozygosity (H) and standardized mean (d²)] influenced both male and female preferences, regardless of mating context. Females preferred males with greater diversity at MHC loci (H) and males preferred females with greater diversity at non-MHC loci (d²) in both contexts. Importantly, these findings provide further support for a special role of the MHC in human sexual selection and suggest that male and female mate preferences may work together to potentially enhance both male and female reproductive success by increasing genetic diversity in offspring.     

Mate preferences and infectious disease: theoretical considerations and evidence in humans

Mate preferences may operate in part to mitigate the threats posed by infectious disease. In this paper, we outline various ways in which preferring healthy mates can offer direct benefits in terms of pathogen avoidance and indirect benefits in terms of heritable immunity to offspring, as well as the costs that may constrain mate preferences for health. We then pay special attention to empirical work on mate preferences in humans given the depth and breadth of research on human mating. We review this literature and comment on the degree to which human mate preferences may reflect preferences for health.     

Beautiful fruits taste good: the aesthetic influences of fruit preferences in humans

Although diversity of fruit/seed colouration has received a great amount of attention since Darwin, little is known about its role in eating preferences in humans. We have determined that humans prefer certain fruits/seeds over others and that their willingness to eat them has been significantly influenced by the perceived aesthetic of the presented fruits and seeds. Participants were unable to discriminate between edible and poisonous fruits/ seeds based on their colour. Females rated all the groups of fruits/seeds as more attractive than males with this supporting the role of females in picking fruit in our evolutionary past. Red fruits were rated as more attractive than green or brown fruits. The results support the idea that fruit/seed colouration plays an important role in plant--disperser coevolution and that aesthetic judgment in humans have been shaped by natural selection.     

Functional and postural lateral preferences in humans: interrelations and life-span age differences

This study aimed to provide data on lateral preferences among older subjects, to analyze age differences, and to determine interrelations between lateral preferences. Four functional preferences (handedness, footedness, eyedness, earedness) and three postural lateral preferences (hand-clasping, arm-folding, leg-crossing) were assessed in 628 Germans (252 men, 376 women) aged between 19 and 90 years. Sex differences, age differences, and associations between lateralities were analyzed applying chi-square tests. Logistic regression analyses considering age, sex, and interactions between variables were applied to analyze combined effects on laterality measures. Right-sided preference for handedness, footedness, eyedness, earedness, and leg-crossing characterized 86.8%, 77.1%, 70.9%, 67.8%, and 56.6%, respectively, of subjects, while a left-sided preference for hand-clasping and arm-folding characterized 56.4% and 60.2%, respectively, of all participants. Results are within the range of other populations. Only footedness differed between the sexes: there were more left-footed men. Older cohorts showed a rightward shift in handedness, eyedness, earedness, and leg-crossing, the opposite for arm-folding. No age-related differences exist in footedness or hand-clasping. Logistic regression models indicate no interaction between age and sex for each laterality measure. The four functional lateralities are significantly interrelated. All also are positively associated with leg-crossing. Conversely, the postural lateralities generally are not correlated, although leg-crossing and arm-folding are, inversely. The observed relationships among lateralities support the hypothesis that handedness, footedness, leg-crossing, and earedness might be aspects of a larger phenotype that is independent of hand-clasping and arm-folding.     

Individual differences in women''s facial preferences as a function of digit ratio and mental rotation ability

The second-to-fourth digit ratio (2D:4D) and mental rotation (MR) ability are sexually dimorphic traits that appear early in development and have been correlated with exposure to prenatal androgens (Grimshaw, Sitarenios, & Finegan, 1995; Lutchmaya, Baron-Cohen, Raggatt, Knickmeyer, & Manning, 2004). The current study examined how 2D:4D and MR differences among women of European descent (N=41) were related to their (a) preferences for male faces: attractive (ATM), short-term (STM), and long-term mate (LTM), and (b) psychological femininity and masculinity, as measured by the Bem Sex-Role Inventory (BSRI) (Bem, 1981). To examine potential changes in facial preferences over their menstrual cycle, participants' preferences were measured during two experimental sessions separated by 2 weeks. The results indicated that (a) femininity scores decreased with decreasing 2D:4D, (b) masculinity scores increased with faster MR, (c) women preferred a more masculine male face for an STM than for an LTM, and (d) preference changes over the menstrual cycle varied systematically with 2D:4D. When compared with women with high 2D:4D ratios, low 2D:4D women (e) preferred a more masculine LTM, (f) recalled less parental bonding, (g) had shorter intimate relationships, and (h) reported more menstrual irregularity. The results are interpreted as support for an interactive hormonal theory of physical attraction.     

Variable preferences for sexual dimorphism in height as a strategy for increasing the pool of potential partners in humans

Human mate preferences are known to be related to a number of morphological traits. Those relating to female waist-to-hip ratio or body mass index and to male height appear to be distinctive mate-choice criteria and are known to be related to reproductive success. In addition to absolute height, a possibly important mate-choice criterion may be relative height, i.e. the extent of sexual dimorphism in stature (SDS = male height/female height) between oneself and a potential partner. Here, I demonstrate that people adjust their preferences for SDS in relation to their own height in order to increase the potential pool of partners. This causes nonlinearity in assortative mating in relation to height and shows that in relation to intrapopulational SDS both men and women are responsible for stabilizing selection.     

Recognition of emotions by facial and verbal samples in healthy humans and patients with local brain pathology

The efficiency of emotion recognition by verbal and facial samples was tested in 81 persons (25 healthy subjects and 56 patients with focal pathology of premotor and temporal areas of brain hemispheres). The involvement of some cortical structures in the recognition of the basic emotional states (joy, anger, grief, and fear) and the neutral state was compared. It was shown that the damage to both right and left hemispheres impaired the recognition of emotional states by not only facial but also verbal samples. Damage to the right premotor area and to the left temporal area impaired the efficiency of the emotion recognition by both kinds of samples to the highest degree.