Inferring social attributes from different face regions: evidence for holistic processing

Two experiments investigated the role that different face regions play in a variety of social judgements that are commonly made from facial appearance (sex, age, distinctiveness, attractiveness, approachability, trustworthiness, and intelligence). These judgements lie along a continuum from those with a clear physical basis and high consequent accuracy (sex, age) to judgements that can achieve a degree of consensus between observers despite having little known validity (intelligence, trustworthiness). Results from Experiment 1 indicated that the face's internal features (eyes, nose, and mouth) provide information that is more useful for social inferences than the external features (hair, face shape, ears, and chin), especially when judging traits such as approachability and trustworthiness. Experiment 2 investigated how judgement agreement was affected when the upper head, eye, nose, or mouth regions were presented in isolation or when these regions were obscured. A different pattern of results emerged for different characteristics, indicating that different types of facial information are used in the various judgements. Moreover, the informativeness of a particular region/feature depends on whether it is presented alone or in the context of the whole face. These findings provide evidence for the importance of holistic processing in making social attributions from facial appearance.     

Effects of inversion and negation on social inferences from faces

Judgments about personality and other social characteristics based on facial appearance are remarkably consistent across individuals. However, whereas the facial cues that underpin age and sex judgments are already well understood, the physical bases for judgments of characteristics such as intelligence or trustworthiness are still unknown. Inversion and photographic negation are used here to investigate the visual processes underlying social inferences from the face and to explore whether various judgments might rely on different perceptual representations. In experiment 1, the perceptions of age, sex, attractiveness, approachability, intelligence, and trustworthiness, but not distinctiveness, were affected by inversion, and all these characteristics were affected by negation. The effects of inversion and negation were independent, suggesting that they impaired the encoding of different types of information. Moreover, an independent manipulation of hue and luminance in experiment 2 showed that the effects of negation were mainly due to the reversal of luminance values. These results are consistent with the view that information about the configuration of features (the processing of which is impaired by inversion) and information about surface properties (the processing of which is impaired by brightness negation) are both used in the perception of social characteristics from faces. In addition, the fact that there was a similar pattern of impairment across most judgments suggests that there is an initial common perceptual representation of the face, from which most characteristics are inferred.     

Exploring the perception of social characteristics in faces using the isolation effect

The age, sex, and distinctiveness of faces can be judged from objective and partially independent facial features. In contrast, the physical basis of other social judgements, such as attractiveness, intelligence, and trustworthiness is not as yet entirely understood, despite the consistency of these judgements from faces. The present set of experiments investigated the perception of social characteristics in faces, using an adaptation of the von Restorff/isolation paradigm to determine which social characteristics are spontaneously encoded from the face. The isolation effect involves enhanced memory for perceptually salient items in a list (items that are isolated in the sense that they are in numeric minority) and our results suggested that its locus is at the encoding stage of the recognition memory experiment. Isolation in the present experiments was achieved by manipulating the number of faces included in the sets on the basis of certain characteristics. Because the manipulation of the characteristics of faces in a set to be learnt was not mentioned in most of the experiments, any resulting memory increment for the isolated items could be taken as an index of spontaneous processing of the manipulated social characteristic. Age and sex were found to be spontaneously encoded from faces. Results for other characteristics were mixed, ranging from distinctiveness and attractiveness, for which there was some indication of spontaneous processing, to intelligence and trustworthiness, which did not seem to be spontaneously encoded from faces. For intelligence, an isolation effect was found only when the experiment required a judgement that led to activation of the appropriate stereotype.     

Normal face-based judgements of social characteristics despite severely impaired holistic face processing

Initial evidence indicates that face-based judgements of socially relevant characteristics such as people's trustworthiness or attractiveness are linked to the configural/holistic processing of facial cues. What remains a matter of debate, however, is whether such processing is actually necessary for normal social judgements to occur and whether it resembles the type of integrative processing as required for facial identification. To address these issues, we asked a well-characterized case of acquired prosopagnosia (PS) with a marked deficit in holistic processing for face identity to rate a series of faces on several dimensions of social relevance. PS provided ratings within the normal range for most of the social characteristics probed (i.e., aggression, attractiveness, confidence, intelligence, sociability, trustworthiness). Her evaluations deviated from those of healthy controls only when facial dominance was concerned. Taken together, these data demonstrate that the inability to integrate facial information during face individuation does not necessarily translate into a generalized deficit to evaluate faces on social dimensions.     

Incidental learning of trust from eye-gaze: Effects of race and facial trustworthiness

Humans rapidly make inferences about individuals’ trustworthiness on the basis of their facial features and perceived group membership. We examine whether incidental learning about trust from shifts in gaze direction is influenced by these facial features. To do so, we examined two types of face category: the race of the face and the initial trustworthiness of the face based on physical appearance. We find that cueing of attention by eye-gaze is unaffected by race or initial levels of trust, whereas incidental learning of trust from gaze behaviour is selectively influenced. That is, learning of trust is reduced for other-race faces, as predicted by reduced abilities to identify members of other races (Experiment 1). In contrast, converging findings from an independently gathered set of data showed that the initial trustworthiness of faces did not influence learning of trust (Experiment 2). These results show that learning about the behaviour of other-race faces is poorer than for own-race faces, but that this cannot be explained by differences in the perceived trustworthiness of different groups.     

The recognition of mental states from dynamic and static facial expressions

The ability to recognize mental states from facial expressions is essential for effective social interaction. However, previous investigations of mental state recognition have used only static faces so the benefit of dynamic information for recognizing mental states remains to be determined. Experiment 1 found that dynamic faces produced higher levels of recognition accuracy than static faces, suggesting that the additional information contained within dynamic faces can facilitate mental state recognition. Experiment 2 explored the facial regions that are important for providing dynamic information in mental state displays. This involved using a new technique to freeze motion in a particular facial region (eyes, nose, mouth) so that this region was static while the remainder of the face was naturally moving. Findings showed that dynamic information in the eyes and the mouth was important and the region of influence depended on the mental state. Processes involved in mental state recognition are discussed.     

Low-level orientation information for social evaluation in face images

Observers make a range of social evaluations based on facial appearance, including judgments of trustworthiness, warmth, competence, and other aspects of personality. What visual information do people use to make these judgments? While links have been made between perceived social characteristics and other high-level properties of facial appearance (e.g., attractiveness, masculinity), there has been comparatively little effort to link social evaluations to low-level visual features, like spatial frequency and orientation sub-bands, known to be critically important for face processing. We explored the extent to which different social evaluations depended critically on horizontal orientation energy vs. vertical orientation energy, as is the case for face identification and emotion recognition. We found that while trustworthiness judgments exhibited this bias for horizontal orientations, competence and dominance did not, suggesting that social evaluations may depend on a multi-channel representation of facial appearance at early stages of visual processing.     

Abnormalities in early visual processes are linked to hypersociability and atypical evaluation of facial trustworthiness: An ERP study with Williams syndrome

Accurate assessment of trustworthiness is fundamental to successful and adaptive social behavior. Initially, people assess trustworthiness from facial appearance alone. These assessments then inform critical approach or avoid decisions. Individuals with Williams syndrome (WS) exhibit a heightened social drive, especially toward strangers. This study investigated the temporal dynamics of facial trustworthiness evaluation in neurotypic adults (TD) and individuals with WS. We examined whether differences in neural activity during trustworthiness evaluation may explain increased approach motivation in WS compared to TD individuals. Event-related potentials were recorded while participants appraised faces previously rated as trustworthy or untrustworthy. TD participants showed increased sensitivity to untrustworthy faces within the first 65–90 ms, indexed by the negative-going rise of the P1 onset (oP1). The amplitude of the oP1 difference to untrustworthy minus trustworthy faces was correlated with lower approachability scores. In contrast, participants with WS showed increased N170 amplitudes to trustworthy faces. The N170 difference to low–high-trust faces was correlated with low approachability in TD and high approachability in WS. The findings suggest that hypersociability associated with WS may arise from abnormalities in the timing and organization of early visual brain activity during trustworthiness evaluation. More generally, the study provides support for the hypothesis that impairments in low-level perceptual processes can have a cascading effect on social cognition.     

Judging approachability on the face of it: the influence of face and body expressions on the perception of approachability

The aim of the current study was to examine how emotional expressions displayed by the face and body influence the decision to approach or avoid another individual. In Experiment 1, we examined approachability judgments provided to faces and bodies presented in isolation that were displaying angry, happy, and neutral expressions. Results revealed that angry expressions were associated with the most negative approachability ratings, for both faces and bodies. The effect of happy expressions was shown to differ for faces and bodies, with happy faces judged more approachable than neutral faces, whereas neutral bodies were considered more approachable than happy bodies. In Experiment 2, we sought to examine how we integrate emotional expressions depicted in the face and body when judging the approachability of face-body composite images. Our results revealed that approachability judgments given to face-body composites were driven largely by the facial expression. In Experiment 3, we then aimed to determine how the categorization of body expression is affected by facial expressions. This experiment revealed that body expressions were less accurately recognized when the accompanying facial expression was incongruent than when neutral. These findings suggest that the meaning extracted from a body expression is critically dependent on the valence of the associated facial expression.     

面孔社会知觉模型发展的回顾与展望

面孔作为一种复杂的特殊刺激,是人类表达自身情绪、认知他人情感的重要工具和途径。面孔识别是人类社会生活的一项重要技能,在缺乏外部线索时,它有助于我们对他人面孔的熟悉度、年龄和种族等方面有一个较明确的认识,从而更有利于人们社会交往和适应环境。大量研究表明,基于面孔的物理特征可以推断面孔所有者的内在特质,而这一推断又会影响个体的行为决策。因此,对面孔的认知不仅要关注面孔结构化特征,也要关注面孔社会化特征。针对面孔结构化特征,学者们提出了一些经典模型,如Bruce-Young模型、NBC模型等;针对面孔社会化特征,Alexander Todorov及其合作者采用主成分分析法,构建了包含信任度和支配度的面孔社会知觉“二维”模型。Clare A.M. Sutherland及其合作者提出,吸引力和信任度是两个独立的维度,由此构建了包含可接近性、年轻的—吸引力和支配度的面孔社会知觉“三维”模型。本文认为,面孔社会知觉模型从“二维”到“三维”的发展可以从吸引力和信任度两个维度的关系进行探讨。面孔在社会互动中传递着大量的信息,其中较为重要的是面孔信任度和面孔吸引力。其中,信任度评价具有决定性意义,信任一个不值得信任的人可能会给自身造成危害,而没信任一个值得信任的人往往意味着失去了合作的机会;吸引力评价则具有进化上的意义,吸引力往往与潜在配偶的繁殖能力有关,尤其体现在长期择偶关系之中。总结以往的面孔识别模型与本文介绍的面孔社会知觉模型,未来基于面孔特征的识别或特质推断可以从以下几方面进行思考：第一,选取生态化效度更高的面孔刺激材料;第二,进行跨文化检验模型的普适性;第三,从面孔识别模型向面孔社会知觉模型的发展需要进一步探索内在的认知神经机制;第四,进一步拓宽面孔社会知觉的研究领域。     

Face recognition memory: The effects of exposure duration and encoding instruction

Two experiments test the effects of exposure duration and encoding instruction on the relative memory for five facial features. Participants viewed slides of Identi-kit faces and were later given a recognition test with same or changed versions of each face. Each changed test face involved a change in one facial feature: hair, eyes, chin, nose or mouth. In both experiments the upper-face features of hair and eyes were better recognized than the lower-face features of nose, mouth, and chin, as measured by false alarm rates. In Experiment 1, participants in the 20-second exposure duration condition remembered faces significantly better than participants in the 3-second exposure duration condition; however, memory for all five facial features improved at a similar rate with the increased duration. In Experiment 2, participants directed to use feature scanning encoding instructions remembered faces significantly better than participants following age judgement instructions; however, the size of the memory advantage for upper facial features was less with feature scanning instructions than with age judgement instructions. The results are discussed in terms of a quantitative difference in processing faces with longer exposure duration, versus a qualitative difference in processing faces with various encoding instructions. These results are related to conditions that affect the accuracy of eyewitness identification.     

The contribution of facial regions to judgements of happiness and trustworthiness from dynamic expressions

What expressive facial features and processing mechanisms make a person look trustworthy, relative to happy? Participants judged the un/happiness or un/trustworthiness of people with dynamic expressions in which the eyes and/or the mouth unfolded from neutral to happy or vice versa. Faces with an unfolding smile looked more trustworthy and happier than faces with a neutral mouth, regardless of the eye expression. Unfolding happy eyes increased both trustworthiness and happiness only in the presence of a congruent unfolding smiling mouth. Nevertheless, the contribution of the mouth was greater for happiness than for trustworthiness; and the mouth was especially visually salient for expressions favouring happiness more than trustworthiness. We conclude that the categorisation of facial happiness is more automatically driven by the visual saliency of a single feature, that is, the smiling mouth, while perception of trustworthiness is more strategic, with the eyes being necessarily incorporated into a configural face representation.     

Age differences in facial trustworthiness judgement based on multiple facial cues

Multiple facial cues such as facial expression and face gender simultaneously influence facial trustworthiness judgement in adults. The current work was to examine the effect of multiple facial cues on trustworthiness judgement across age groups. Eight-, 10-year-olds, and adults detect trustworthiness from happy and neutral adult faces (female and male faces) in Experiment 1. Experiment 2 included both adult and child faces wearing happy, angry, and neutral expressions. Nine-, 11-, 13-year-olds, and adults had to rate facial trustworthiness with a 7-point Likert scale. The results of Experiments 1 and 2 revealed that facial expression and face gender independently affected facial trustworthiness judgement in children aged 10 and below but simultaneously affected judgement in children aged 11 and above, adolescents, and adults. There was no own-age bias in children and adults. The results showed that children younger than 10 could not process multiple facial cues in the same manner as in older children and adults when judging trustworthiness. The current findings provide evidence for the stable-feature account, but not for the own-age bias account or the expertise account.     

The first 100 milliseconds of a face: on the microgenesis of early face processing

Face recognition involves both processing of information relating to features (e.g., eyes, nose, mouth, hair, i.e., featural processing), as well as the spatial relation between these features (configural processing). In a sequential matching task, participants had to decide whether two faces that differed in either featural or relational aspects were identical or different. In order to test for the microgenesis of face recognition (the development of processing onsets), presentation times of the backward-masked target face were varied (32, 42, 53, 63, 74, 84, or 94 msec.). To test for specific processing onsets and the processing of different facial areas, both featurally and relationally modified faces were manipulated in terms of changes to one facial area (eyes or nose or mouth), two, or three facial areas. For featural processing, an early onset for the eyes and mouth was at 32 msec. of presentation time, but a late onset for the nose was detected. For relationally differing faces, all onsets were delayed.     

The dissociable influence of social context on judgements of facial attractiveness and trustworthiness

The cheerleader effect occurs when the same face is rated to be more attractive when it is seen in a group compared to when seen alone. We investigated whether this phenomenon also occurs for trustworthiness judgements, and examined how these effects are influenced by the characteristics of the individual being evaluated and those of the group they are seen in. Across three experiments, we reliably replicated the cheerleader effect. Most faces became more attractive in a group. Yet, the size of the cheerleader effect that each face experienced was not related to its own attractiveness, nor to the attractiveness of the group or the group’s digitally averaged face. We discuss the implications of our findings for the hierarchical encoding and contrast mechanisms that have previously been used to explain the cheerleader effect. Surprisingly, judgements of facial trustworthiness did not experience a ‘cheerleader effect’. Instead, we found that untrustworthy faces became significantly more trustworthy in all groups, while there was no change for faces that were already trustworthy alone. Taken together, our results demonstrate that social context can have a dissociable influence on our first impressions, depending on the trait being evaluated.     

Recovering faces from memory: the distracting influence of external facial features

Recognition memory for unfamiliar faces is facilitated when contextual cues (e.g., head pose, background environment, hair and clothing) are consistent between study and test. By contrast, inconsistencies in external features, especially hair, promote errors in unfamiliar face-matching tasks. For the construction of facial composites, as carried out by witnesses and victims of crime, the role of external features (hair, ears, and neck) is less clear, although research does suggest their involvement. Here, over three experiments, we investigate the impact of external features for recovering facial memories using a modern, recognition-based composite system, EvoFIT. Participant-constructors inspected an unfamiliar target face and, one day later, repeatedly selected items from arrays of whole faces, with "breeding," to "evolve" a composite with EvoFIT; further participants (evaluators) named the resulting composites. In Experiment 1, the important internal-features (eyes, brows, nose, and mouth) were constructed more identifiably when the visual presence of external features was decreased by Gaussian blur during construction: higher blur yielded more identifiable internal-features. In Experiment 2, increasing the visible extent of external features (to match the target's) in the presented face-arrays also improved internal-features quality, although less so than when external features were masked throughout construction. Experiment 3 demonstrated that masking external-features promoted substantially more identifiable images than using the previous method of blurring external-features. Overall, the research indicates that external features are a distractive rather than a beneficial cue for face construction; the results also provide a much better method to construct composites, one that should dramatically increase identification of offenders.     

Developmental changes in the perception of adult facial age

The author studied children's (aged 5-16 years) and young adults' (aged 18-22 years) perception and use of facial features to discriminate the age of mature adult faces. In Experiment 1, participants rated the age of unaltered and transformed (eyes, nose, eyes and nose, and whole face blurred) adult faces (aged 20-80 years). In Experiment 2, participants ranked facial age sets (aged 20-50, 20-80, and 50-80 years) that had varying combinations of older and younger facial features: eyes, noses, mouths, and base faces. Participants of all ages attended to similar facial features when making judgments about adult facial age, although young children (aged 5-7 years) were less accurate than were older children (aged 9-11 years), adolescents (aged 13-16 years), and young adults when making facial age judgments. Young children were less sensitive to some facial features when making facial age judgments.     

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.     

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.