D. Michael Burt

Symmetry and human facial attractiveness

Abstract Symmetry may act as a marker of phenotypic and genetic quality and is preferred during mate selection in a variety of species. Measures of human body symmetry correlate with attractiveness, but studies manipulating human face images report a preference for asymmetry. These results may reflect unnatural feature shapes and changes in skin textures introduced by image processing. When the shape of facial features is varied (with skin textures held constant), increasing symmetry of face shape increases ratings of attractiveness for both male and female faces. These findings imply facial symmetry may have a positive impact on mate selection in humans.

Is everybody always my friend? Perception of approachability in Williams syndrome

Individuals with Williams syndrome (WS) are well known for their friendly behaviour and tendency to approach strangers indiscriminately as if everybody were their friend. This tendency to approach strangers is mirrored in their ratings of unfamiliar face stimuli. Here we examined their perception of unfamiliar expressive faces and found that individuals with WS do not always see faces as being highly approachable. Happy faces were rated as more approachable by individuals with WS than by controls. In contrast, the other less approachable face stimuli were rated lower on approachability by individuals with WS than by controls. Thus, it appears that although individuals with WS will discriminate people in terms of approachability, they have difficulty inhibiting their strong compulsion towards social interaction. The form of this strong pro-social compulsion is discussed both in terms of friendliness and in terms of the heightened salience of social stimuli (social stimulus attraction).

Facial expression recognition in Williams syndrome

Individuals with Williams syndrome (WS) excel in face recognition and show both a remarkable concern for social stimuli and a linguistic capacity for, in particular, emotionally referenced language. The animated full facial expression comprehension test (AFFECT), a new test of emotional expression perception, was used to compare participants with WS with both chronological and mental age-matched controls. It was found that expression recognition in WS was worse than that of chronologically age-matched controls but indistinguishable from that of mental age controls. Different processing strategies are thought to underlie the similar performance of individuals with WS and mental age controls. The expression recognition performance of individuals with WS did not correlate with age, but was instead found to correlate with IQ. This is compared to earlier findings, replicated here, that face recognition performance on the Benton test correlates with age and not IQ. The results of the Benton test have been explained in terms of individuals with WS being good at face recognition; since a piecemeal strategy can be used, this strategy is improved with practice which would explain the correlation with age. We propose that poor expression recognition of the individuals with WS is due to a lack of configural ability since changes in the configuration of the face are an important part of expressions. Furthermore, these reduced configural abilities may be due to abnormal neuronal development and are thus fixed from an early age.

Facial attractiveness judgements reflect learning of parental age characteristics

Mate preferences are shaped by infant experience of parental characteristics in a wide variety of species. Similar processes in humans may lead to physical similarity between parents and mates, yet this possibility has received little attention. The age of parents is one salient physical characteristic that offspring may attend to. The current study used computer–graphic faces to examine how preferences for age in faces were influenced by parental age. We found that women born to ‘old’ parents (over 30) were less impressed by youth, and more attracted to age cues in male faces than women with ‘young’ parents (under 30). For men, preferences for female faces were influenced by their mothers age and not their fathers age, but only for long–term relationships. These data indicate that judgements of facial attractiveness in humans reflect the learning of parental characteristics.

Preferences for symmetry in faces change across the menstrual cycle

Symmetry in human male faces may be a cue to heritable fitness benefits and is found attractive. Preferences for facial masculinity, another proposed marker of genetic quality, have been found to vary in ways that may maximise evolutionary relevant benefits and masculinity is found to be of increased attractiveness at peak fertility across the menstrual cycle. Here we show that women prefer more symmetric faces at peak fertility (Study 1) and that such shifting preferences may be potentially strategic preferences as we found them to occur only for judgements concerning short-term relations and when women already had a partner (Study 2). Such preferences potentially indicate a strategy that maximises the quality of extra-pair/short-term partners or a quality dependent response to hormones. Such strategic preferences for symmetry may support the role of symmetry in signalling potential good-gene benefits.

Concordant preferences for opposite–sex signals? Human pheromones and facial characteristics

We have investigated whether preferences for masculine and feminine characteristics are correlated across two modalities, olfaction and vision. In study 1, subjects rated the pleasantness of putative male (4,16–androstadien–3–one; 5α–androst–16–en–3–one) and female (1,3,5(10),16–estratetraen–3–ol) pheromones, and chose the most attractive face shape from a masculine–feminine continuum for a long– and a short–term relationship. Study 2 replicated study 1 and further explored the effects of relationship context on pheromone ratings. For long–term relationships, womens preferences for masculine face shapes correlated with ratings of 4,16–androstadien–3–one and mens preferences for feminine face shapes correlated with ratings of 1,3,5(10),16–estratetraen–3–ol. These studies link sex–specific preferences for putative human sex pheromones and sexually dimorphic facial characteristics. Our findings suggest that putative sex pheromones and sexually dimorphic facial characteristics convey common information about the quality of potential mates.

Asymmetric interference between sex and emotion in face perception

Previous research with speeded-response interference tasks modeled on the Garner paradigm has demonstrated that task-irrelevant variations in either emotional expression or facial speech do not interfere with identity judgments, but irrelevant variations in identity do interfere with expression and facial speech judgments. Sex, like identity, is a relatively invariant aspect of faces. Drawing on a recent model of face processing according to which invariant and changeable aspects of faces are represented in separate neurological systems, we predicted asymmetric interference between sex and emotion classification. The results of Experiment 1, in which the Garner paradigm was employed, confirmed this prediction: Emotion classifications were influenced by the sex of the faces, but sex classifications remained relatively unaffected by facial expression. A second experiment, in which the difficulty of the tasks was equated, corroborated these findings, indicating that differences in processing speed cannot account for the asymmetric relationship between facial emotion and sex processing. A third experiment revealed the same pattern of asymmetric interference through the use of a variant of the Simon paradigm. To the extent that Garner interference and Simon interference indicate interactions at perceptual and response-selection stages of processing, respectively, a challenge for face processing models is to show how the same asymmetric pattern of interference could occur at these different stages. The implications of these findings for the functional independence of the different components of face processing are discussed.

Age Effects on Emotion Recognition in Facial Displays: From 20 to 89 Years of Age

Background/Study Context: An emotion recognition task that morphs emotional facial expressions from an initial neutral expression to distinct increments of the full emotional expression was administered to 482 individuals, 20 to 89 years of age. Methods: Participants assessed six basic emotions at 25%, 50%, 75%, and 100% of the full facial expression. Results: Participants in the three oldest age groups (60s, 70s, and 80s) demonstrated decreased performance for the recognition of the fear, anger, and sad emotions. Increased age was associated with increased recognition rates for the disgust expression, whereas no age effect was detected for the happy and surprise expressions. Covariate analyses revealed age effects were reduced by processing speed, but were unaffected by decision-making ability. The effects of age on individual emotions and levels of presentation are discussed. Conclusion: These findings suggest that age has the greatest impact on the recognition of the sad emotion and the greatest age effect at the 50% level of presentation across the adult life span.

Testing immunocompetence explanations of male facial masculinity

Abstract Currently the Immunocompetence Hypothesis dominates research into female attraction to male facial masculinity. Although studies have shown links between masculinity and possible indicators of health such as fluctuating asymmetry, preferences for facial masculinity do not co-vary with preferences for apparent health (BOOTHROYD et al. 2005). Here we build on that work with two studies. Study 1 addresses the concern that apparent health may not fully reflect long term immune function by investigating how masculinity preferences correlate with preferences for other potential indicators of ‘good genes’: symmetry and averageness. Study 2 investigated whether masculinity preferences were dependant upon the presence of other indicators of ‘good immunity’ in the face, by showing observers both symmetric and asymmetric masculinity stimuli. Across three samples, womens masculinity preferences were inversely correlated with symmetry preferences, counter to prediction, and there were no consistent associati...

Asymmetry in face processing during childhood measured with chimeric faces.

Studies with adults have found a left bias in their perception of faces, which suggests a right hemisphere specialisation in processing facial information. Hemispheric asymmetry is observed during the first year of life but it is still unclear at what age such specialisation becomes adult-like during the prolonged period of face-processing development through childhood. In the present study we investigated the development of childrens perceptions of gender and emotion using chimeric faces. Our results demonstrate that a right hemisphere bias, similar to that found in adults, is observed from 5 years of age. The results are discussed within a framework of developmental studies and we conclude that although children may be less efficient than adults at encoding faces, their basic manner of encoding is not fundamentally different from that of adults.