Age estimation of faces: a review

The effect of processing partial information in dynamic face perception

Face perception is a major topic in vision research. Most previous research has concentrated on (holistic) spatial representations of faces, often with static faces as stimuli. However, faces are highly dynamic stimuli containing important temporal information. How sensitive humans are regarding temporal information in dynamic faces is not well understood. Studies investigating temporal information in dynamic faces usually focus on the processing of emotional expressions. However, faces also contain relevant temporal information without any strong emotional expression. To investigate cues that modulate human sensitivity to temporal order, we utilized muted dynamic neutral face videos in two experiments. We varied the orientation of the faces (upright and inverted) and the presence/absence of eye blinks as partial dynamic cues. Participants viewed short, muted, monochromic videos of models vocalizing a widely known text (National Anthem). Videos were played either forward (in the correct temporal order) or backward. Participants were asked to determine the direction of the temporal order for each video, and (at the end of the experiment) whether they had understood the speech. We found that face orientation, and the presence/absence of an eye blink affected sensitivity, criterion (bias) and reaction time: Overall, sensitivity was higher for upright compared to inverted faces, and in the condition where an eye blink was present compared to the condition without an eye blink. Reaction times were mostly faster in the conditions with higher sensitivity. A bias to report inverted faces as 'backward' observed in Experiment I, where upright and inverted faces were presented randomly interleaved within each block, was absent when presenting upright and inverted faces in different blocks in Experiment II. Language comprehension results revealed that there was higher sensitivity when understanding the speech compared to not understanding the speech in both experiments. Taken together, our results showed higher sensitivity with upright compared to inverted faces, suggesting that the perception of dynamic, task-relevant information was superior with the canonical orientation of the faces. Furthermore, partial information coming from eye blinks, in addition to mouth movements, seemed to play a significant role in dynamic face perception, both when faces were presented upright and inverted. We suggest that studying the perception of facial dynamics beyond emotional expressions will help us to better understand the mechanisms underlying the temporal integration of facial information from different -partial and holistic- sources, and that our results show how different strategies, depending on the available information, are employed by human observers when judging the temporal order of faces.

The role of facial skin tone and texture in the perception of age

Age and gender perception from looking at people's faces, without any cultural or conventional cues, is primarily based on two independent components: a) the shape or facial structure, and b) surface reflectance (skin tone and texture, STT). This study examined the relative contribution of facial STT to the perception of age. A total of 204 subjects participated in four experiments presenting artificial 3D realistic faces of different age versions under two key experimental conditions: with and without STT. Two experiments involved a discrimination-age task, and other two involved a direct age-estimation task. The faces for the last experiment were generated from the photographs of real people. The results were quite consistent throughout the experiments. Data suggest that the contribution of the STT information leads to roughly 25-33 % of accuracy in age perception. Interestingly, a differential pattern emerges in relation to facial age: the relative contribution of skin information increases sharply with advancing age, to the point that age judgments of the older faces (60 years old) without STT information fall to the chance level. This pattern suggests that facial skin tone and texture are the main sources of information for estimating the age of people past their maturity as those are the principal visual signs of aging beyond the anatomical changes of facial structure.

Contextual and own-age effects in age perception

Our judgement of certain facial characteristics such as emotion, attractiveness or age, is affected by context. Faces that are flanked by younger faces, for example, are perceived as being younger, whereas faces flanked by older faces are perceived as being older. Here, we investigated whether contextual effects in age perception are moderated by own age effects. On each trial, a target face was presented on the screen, which was flanked by two faces. Flanker faces were either identical to the target face, were 10 years younger or 10 years older than the target face. We asked 40 older (64–69 years) and 43 younger adults (24–29) to estimate the age of the target face. Our results replicated previous studies and showed that context affects age estimation of faces flanked by target faces of different ages. These context effects were more pronounced for younger compared to older flankers but present across both tested age groups. An own-age advantage was observed for older adults for unflanked faces who had larger estimation errors for younger faces compared to older faces and younger adults. Flanker effects, however, were not moderated by own-age effects. It is likely that the increased effect of younger flankers is due to mechanisms related to perceptual averaging.

An Examination of the Synergy of Age and PTSD on Narrative Coherence in Child Sexual Abuse Testimony

In a criminal proceeding, a witness is considered as reliable if he/she can recall in narrative form the events, chronologically ordered, with salient contextual (place and time) details, and essential evaluations for the definition of meanings. This study aimed to confirm the effects of age and PTSD on narrative coherence and to investigate the moderating role of age on the association between PTSD and narrative coherence. Narrative coherence was analyzed in 92 allegations of children (M = 10.3; range: 4-17), who were victims of sexual abuse. Thirty-five children presented the symptoms for a diagnosis of PTSD. Each deposition has been codified through the Narrative Coherence Coding Scheme, a coding scheme based on the three independent dimensions (context, chronology, and theme). Correlation analysis indicated the positive associations between age and context, chronology, and theme; and the negative associations between PTSD symptoms and context, chronology, and theme. Predictive effect of PTSD became less and less significant with increasing age. This study could underline the importance of age and PTSD (and their synergy) in legal testimony of children who have been sexually abused.

What happens to our representation of identity as familiar faces age? Evidence from priming and identity aftereffects

Matching identity in images of unfamiliar faces is error prone, but we can easily recognize highly variable images of familiar faces - even images taken decades apart. Recent theoretical development based on computational modelling can account for how we recognize extremely variable instances of the same identity. We provide complementary behavioural data by examining older adults' representation of older celebrities who were also famous when young. In Experiment 1, participants completed a long-lag repetition priming task in which primes and test stimuli were the same age or different ages. In Experiment 2, participants completed an identity after effects task in which the adapting stimulus was an older or young photograph of one celebrity and the test stimulus was a morph between the adapting identity and a different celebrity; the adapting stimulus was the same age as the test stimulus on some trials (e.g., both old) or a different age (e.g., adapter young, test stimulus old). The magnitude of priming and identity after effects were not influenced by whether the prime and adapting stimulus were the same age or different age as the test face. Collectively, our findings suggest that humans have one common mental representation for a familiar face (e.g., Paul McCartney) that incorporates visual changes across decades, rather than multiple age-specific representations. These findings make novel predictions for state-of-the-art algorithms (e.g., Deep Convolutional Neural Networks).

Are estimates of faces' ages less accurate when they wear sunglasses or face masks and do these disguises make it harder to later recognise the faces when undisguised?

This study examined whether our ability to accurately estimate unfamiliar faces' ages declines when they are wearing sunglasses or surgical-style face masks and whether these disguises make it harder to later recognise those faces when undisguised. In theory, both disguises should harm age estimation accuracy and later face recognition as they occlude facial information that is used to determine a face's age and identity. To establish whether this is the case, we had participants estimate the age of unfamiliar faces that were pictured wearing no disguises, sunglasses, or face masks. The participants then completed a face recognition test where they had to distinguish between the previously seen faces and new faces. Importantly, none of faces wore disguises in this latter test. Participants' estimates of the undisguised faces' ages were inaccurate by a Median of 5.15 years. Their accuracy barely changed when the faces wore sunglasses but declined by a Median of 1.30 years when they wore face masks. Moreover, subsequent undisguised face recognition was less likely to occur when the faces previously wore sunglasses or face masks, with large effects observed. These findings demonstrate the relative importance of different facial areas when estimating faces' ages and later recognising them. They also have implications for policing as they suggest it may be harder for eyewitnesses to accurately estimate the age of criminals who wear face masks during offences, and it may be harder for them to later recognise criminals in line-ups if the criminals wear sunglasses or face masks during offences.

Your ID , please? The effect of Facemasks and Makeup on Perceptions of Age of Young Adult Female Faces

During the COVID‐19 pandemic, wearing facemasks was mandatory in the United Kingdom except for individuals with medical exemptions. Facemasks cover the full lower half of the face; however, the effect of facemasks on age perception is not yet known. The present study examined whether age estimation accuracy of unfamiliar young adult women is impaired when the target is wearing a facemask. This study also examined whether makeup, which has previously been shown to increase error bias, further impairs age estimation accuracy when paired with a facemask. The findings indicate that both facemasks and makeup tend to result in overestimation of the young women's age compared to neutral faces, but the combination of both is not additive. Individual level analysis also revealed large individual differences in age estimation accuracy ranging from estimates within 1 year of the target's actual age, and age estimates which deviated by up to 20 years.

No evidence of spatial representation of age, but "own-age bias" like face processing found in chimpanzees

Previous studies have revealed that non-human primates can differentiate the age category of faces. However, the knowledge about age recognition in non-human primates is very limited and whether non-human primates can process facial age information in a similar way to humans is unknown. As humans have an association between time and space (e.g., a person in an earlier life stage to the left and a person in a later life stage to the right), we investigated whether chimpanzees spatially represent conspecifics’ adult and infant faces. Chimpanzees were tested using an identical matching-to-sample task with conspecific adult and infant face stimuli. Two comparison images were presented vertically (Experiment 1) or horizontally (Experiment 2). We analyzed whether the response time was influenced by the position and age category of the target stimuli, but there was no evidence of correspondence between space and adult/infant faces. Thus, evidence of the spatial representation of the age category was not found. However, we did find that the response time was consistently faster when they discriminated between adult faces than when they discriminated between infant faces in both experiments. This result is in line with a series of human face studies that suggest the existence of an “own-age bias.” As far as we know, this is the first report of asymmetric face processing efficiency between infant and adult faces in non-human primates.

Male or Female? - Influence of Gender Role and Sexual Attraction on Sex Categorization of Faces

The categorization of dominant facial features, such as sex, is a highly relevant function for social interaction. It has been found that attributes of the perceiver, such as their biological sex, influence the perception of sexually dimorphic facial features with women showing higher recognition performance for female faces than men. However, evidence on how aspects closely related to biological sex influence face sex categorization are scarce. Using a previously validated set of sex-morphed facial images (morphed from male to female and vice versa), we aimed to investigate the influence of the participant's gender role identification and sexual orientation on face sex categorization, besides their biological sex. Image ratings, questionnaire data on gender role identification and sexual orientation were collected from 67 adults (34 females). Contrary to previous literature, biological sex per se was not significantly associated with image ratings. However, an influence of participant sexual attraction and gender role identity became apparent: participants identifying with male gender attributes and showing attraction toward females perceived masculinized female faces as more male and femininized male faces as more female when compared to participants identifying with female gender attributes and attraction toward males. Considering that we found these effects in a predominantly cisgender and heterosexual sample, investigation of face sex perception in individuals identifying with a gender different from their assigned sex (i.e., transgender people) might provide further insights into how assigned sex and gender identity are related.

Differences between perceived age and chronological age in women: A multi-ethnic and multi-centre study

Objective

Accuracy in assessing age from facial cues is important in social perception given reports of strong negative correlations between perceived age and assessments of health and attractiveness. In a multi‐ethnic and multi‐centre study, we previously documented similar patterns of female facial age assessments across ethnicities, influenced by gender and ethnicity of assessors.

Methods

Here we extend these findings by examining differences between estimated age from digital portraits and chronological age (Δ age) for 180 women from three age groups (20–34, 35–49, 50–66 years) and five ethnicities (36 images of each ethnicity, assessed for age on a continuous scale by 120 female and male raters of each ethnicity).

Results

Across ethnicities, Δ age was smallest in French assessors and largest in South African assessors. Numerically, French women were judged oldest and Chinese women youngest relative to chronological age. In younger women, Δ age was larger than in middle‐aged and older women. This effect was particularly evident when considering the interaction of women's age with assessor gender and ethnicity, independently and together, on Δ age.

Conclusion

Collectively, our findings suggest that accuracy in assessments of female age from digital portraits depends on the chronological age and ethnicity of the photographed women and the ethnicity and gender of the assessor. We discuss the findings concerning ethnic variation in skin pigmentation and visible signs of ageing and comment on implications for cosmetic science.

Human brain activity reflecting facial attractiveness from skin reflection

Facial attraction has a great influence on our daily social interactions. Previous studies have mainly focused on the attraction from facial shape and expression. We recently found that faces with radiant skin appear to be more attractive than those with oily-shiny or matte skin. In the present study, we conducted functional magnetic resonance imaging (fMRI) and psychological experiments to determine the human brain activity that reflects facial attractiveness modulated by these skin reflection types. In the fMRI experiment, female subjects were shown successive images of unfamiliar female faces with matte, oily-shiny, or radiant skin. The subjects compared each face with the immediately preceding face in terms of attractiveness, age, and skin reflection, all based on the skin. The medial part of the orbitofrontal cortex (mOFC) was significantly more active when comparing attractiveness than when comparing skin reflection, suggesting that the mOFC is involved in processing facial attractiveness from skin reflection. In the psychological experiment, attractiveness rating was highest for radiant skin, followed by oily-shiny, and then matte skin. Comparison of the results of these experiments showed that mOFC activation level increased with attractiveness rating. These results suggest that the activation level of the mOFC reflects facial attractiveness from skin reflection.

Robust Active Shape Model via Hierarchical Feature Extraction with SFS-Optimized Convolution Neural Network for Invariant Human Age Classification

The features and appearance of the human face are affected greatly by aging. A human face is an important aspect for human age identification from childhood through adulthood. Although many traits are used in human age estimation, this article discusses age classification using salient texture and facial landmark feature vectors. We propose a novel human age classification (HAC) model that can localize landmark points of the face. A robust multi-perspective view-based Active Shape Model (ASM) is generated and age classification is achieved using Convolution Neural Network (CNN). The HAC model is subdivided into the following steps: (1) at first, a face is detected using aYCbCr color segmentation model; (2) landmark localization is done on the face using a connected components approach and a ridge contour method; (3) an Active Shape Model (ASM) is generated on the face using three-sided polygon meshes and perpendicular bisection of a triangle; (4) feature extraction is achieved using anthropometric model, carnio-facial development, interior angle formulation, wrinkle detection and heat maps; (5) Sequential Forward Selection (SFS) is used to select the most ideal set of features; and (6) finally, the Convolution Neural Network (CNN) model is used to classify according to age in the correct age group. The proposed system outperforms existing statistical state-of-the-art HAC methods in terms of classification accuracy, achieving 91.58% with The Images of Groups dataset, 92.62% with the OUI Adience dataset and 94.59% with the FG-NET dataset. The system is applicable to many research areas including access control, surveillance monitoring, human–machine interaction and self-identification.

Asymmetric contextual effects in age perception

Perception is context dependent. For example, the perceived orientation of a bar changes depending on the presence of oriented bars around it. Contextual effects have also been demonstrated for more complex judgements, such as facial attractiveness or expression, although it remains unclear how these contextual facial effects depend on the types of faces surrounding the target face. To examine this, we measured the perceived age (a quantifiable measure) of a target face in the presence of differently aged faces in the surround. Using a unique database of standardized passport photos, participants were asked to estimate the age of a target face which was viewed either on its own or surrounded by two different identity flanker faces. The flanker faces were either both younger or both older than the target face, with different age offsets between flankers and targets of ±5, ±10, ±15, ±20 years. We find that when a target face is surrounded by younger faces, it systematically appears younger than when viewed on its own, and when it is surrounded by older faces, it systematically appears older than when viewed on its own. Surprisingly, we find that the magnitude of the flanker effects on perceived age of the target is asymmetric with younger flankers having a greater influence than older flankers, a result that may reflect the participants' own-age bias, since all participants were young. This result holds irrespective of gender or race of the faces and is consistent with averaging.

The external phenotype of aging

Aging is widely studied as a physiological process. Segmental aging can also occur prematurely in Mendelian disorders, and these can act this way as excellent sources of information, specifically for the underlying mechanisms. Adequate recognition of such aging characteristics in Mendelian disorders needs a well-defined phenotype of aging. Here the external phenotype of aging is described that can be recognized in the consulting room without major additional studies. Existing definitions of the signs and symptoms in Elements of Morphology or Human Phenotype Ontology are added or a new definition is suggested if none is available.

A cross-cultural investigation into the influence of eye gaze on working memory for happy and angry faces

Previous long-term memory (LTM) research found that angry faces were more poorly recognised when encoded with averted vs. direct gaze, while memory for happy faces was unaffected by gaze. Contrastingly, working memory (WM) accuracy for angry faces was unaffected by gaze, but WM was enhanced for happy faces with averted vs. direct gaze. Because the LTM study was conducted in an Eastern culture (Japan) with Japanese faces, while the WM study was conducted in a Western culture (UK) with Caucasian faces, here we investigated WM further to examine whether gaze effects diverge due to cultural variation between the faces and participants. When Western participants viewed Japanese faces (Experiment 1), the happy-averted gaze advantage in WM was replicated. In contrast, Japanese participants viewing Caucasian faces (Experiment 2a) showed poorer WM for angry faces with averted vs. direct gaze, and no influence of gaze on WM for happy faces. When Japanese participants viewed Japanese faces (Experiment 2b), gaze did not modulate WM. Therefore, the way in which expression and gaze interact to influence face WM does not appear to rely on the specific memory system engaged, but instead may be attributed to cultural differences in display rules between Eastern and Western cultures.

Carotenoid skin colouration enhances face and body attractiveness: A cross-cultural study

Previous research has indicated that faces with higher levels of skin carotenoid colouration are perceived as healthier and more attractive. However, it is not known whether this preference is specific to faces or reflects a more generalised preference in biological stimuli: for example, non-face body parts. Moreover, it is not yet well established whether the preference for carotenoid colouration extends beyond Caucasian populations. Three studies were conducted to address these issues. In Studies 1 and 2, Caucasian and Hong Kong Chinese participants, respectively, selected the more attractive image in pairs of high and low carotenoid colouration versions of images of Caucasian faces and body parts, and also for non-face/body-part control stimuli (scrambled faces). In Study 3, a similar study protocol was used with an independent sample of Hong Kong Chinese participants using stimuli generated from Chinese individuals. The results showed that high carotenoid colouration was preferred across all the three studies in faces and body parts, but not in the control stimuli. In addition, there was a stronger preference for high carotenoid colouration in faces compared with body parts in Studies 1 and 2-although this preference was not observed in Study 3. Overall, these findings demonstrate that higher levels of skin carotenoid colouration are preferred both in face and body parts, but not in non-face stimuli, and that these preferences are evident in Caucasian and Hong Kong Chinese individuals.

Facial cues to age perception using three-dimensional analysis

To clarify cues for age perception, the three-dimensional head and face forms of Japanese women were analyzed. It is known that age-related transformations are mainly caused by changes in soft tissue during adulthood. A homologous polygon model was created by fitting template meshes to each study participant to obtain three-dimensional data for analyzing whole head and face forms. Using principal component analysis of the vertices coordinates of these models, 26 principal components were extracted (contribution ratios >0.5%), which accounted for more than 90% of the total variance. Among the principal components, five had a significant correlation with the perceived ages of the participants (p < 0.05). Transformations with these principal components in the age-related direction produced aged faces. Moreover, the older the perceived age, the larger the ratio of age-manifesting participants, namely participants who had one or more age-related principal component score greater than +1.0 σ in the age-related direction. Therefore, these five principal components were regarded as aging factors. A cluster analysis of the five aging factors revealed that all of the participants fell into one of four groups, meaning that specific combinations of factors could be used as cues for age perception in each group. These results suggest that Japanese women can be classified into four groups according to age-related transformations of soft tissue in the face.

No Own-Age Bias in Children's Gaze-Cueing Effects

Sensitivity to another person's eye gaze is vital for social and language development. In this eye-tracking study, a group of 74 children (6-14 years old) performed a gaze-cueing experiment in which another person's shift in eye gaze potentially cued the location of a peripheral target. The aim of the present study is to investigate whether children's gaze-cueing effects are modulated by the other person's age. In half of the trials, the gaze cue was given by adult models, in the other half of the trials by child models. Regardless of the models' ages, children displayed an overall gaze-cueing effect. However, results showed no indication of an own-age bias in the performance on the gaze-cueing task; the gaze-cueing effect is similar for both child and adult face cues. These results did not change when we looked at the performance of a subsample of participants (n = 23) who closely matched the age of the child models. Our results do not allow us to disentangle the possibility that children are insensitive to a model's age or whether they consider models of either age as equally informative. Future research should aim at trying to disentangle these two possibilities.

Evidence for a young adult face bias in accuracy and consensus of age estimates

Adults' face processing may be specialized for the dimensions of young adult faces. For example, young and older adults exhibit increased accuracy in normality judgments and greater agreement in attractiveness ratings for young versus older adult faces. The present study was designed to examine whether there is a similar young adult face bias in facial age estimates. In Experiment 1, we created a face age continuum by morphing an averaged young adult face with an averaged older adult face in 5% increments, for a total of 21 faces ranging from 0 to 100% old. Young and older adults estimated facial age for three stimulus age categories [young (morphs 0-30%), middle-aged (morphs 35-65%), and older adult (morphs 70-100%)]. Both age groups showed the least differentiation in age estimates for young adult faces, despite showing greater consensus across participants in estimates for young faces. In Experiment 2, young and older adults made age estimates for individual young and older adult identities. Both age groups were more accurate and showed greater consensus in age estimates for young faces. Collectively, these results provide evidence for a bias in processing young adult faces beyond that which is often observed in recognition and normality/attractiveness judgment tasks.

Inter-rater agreement in trait judgements from faces

Researchers have long been interested in how social evaluations are made based upon first impressions of faces. It is also important to consider the level of agreement we see in such evaluations across raters and what this may tell us. Typically, high levels of inter-rater agreement for facial judgements are reported, but the measures used may be misleading. At present, studies commonly report Cronbach's α as a way to quantify agreement, although problematically, there are various issues with the use of this measure. Most importantly, because researchers treat raters as items, Cronbach's α is inflated by larger sample sizes even when agreement between raters is fixed. Here, we considered several alternative measures and investigated whether these better discriminate between traits that were predicted to show low (parental resemblance), intermediate (attractiveness, dominance, trustworthiness), and high (age, gender) levels of agreement. Importantly, the level of inter-rater agreement has not previously been studied for many of these traits. In addition, we investigated whether familiar faces resulted in differing levels of agreement in comparison with unfamiliar faces. Our results suggest that alternative measures may prove more informative than Cronbach's α when determining how well raters agree in their judgements. Further, we found no apparent influence of familiarity on levels of agreement. Finally, we show that, like attractiveness, both trustworthiness and dominance show significant levels of private taste (personal or idiosyncratic rater perceptions), although shared taste (perceptions shared with other raters) explains similar levels of variance in people's perceptions. In conclusion, we recommend that researchers investigating social judgements of faces consider alternatives to Cronbach's α but should also be prepared to examine both the potential value and origin of private taste as these might prove informative.

Facial Asymmetry-Based Age Group Estimation: Role in Recognizing Age-Separated Face Images

Face recognition aims to establish the identity of a person based on facial characteristics. On the other hand, age group estimation is the automatic calculation of an individual's age range based on facial features. Recognizing age-separated face images is still a challenging research problem due to complex aging processes involving different types of facial tissues, skin, fat, muscles, and bones. Certain holistic and local facial features are used to recognize age-separated face images. However, most of the existing methods recognize face images without incorporating the knowledge learned from age group estimation. In this paper, we propose an age-assisted face recognition approach to handle aging variations. Inspired by the observation that facial asymmetry is an age-dependent intrinsic facial feature, we first use asymmetric facial dimensions to estimate the age group of a given face image. Deeply learned asymmetric facial features are then extracted for face recognition using a deep convolutional neural network (dCNN). Finally, we integrate the knowledge learned from the age group estimation into the face recognition algorithm using the same dCNN. This integration results in a significant improvement in the overall performance compared to using the face recognition algorithm alone. The experimental results on two large facial aging datasets, the MORPH and FERET sets, show that the proposed age group estimation based on the face recognition approach yields superior performance compared to some existing state-of-the-art methods.

The phone walkers: a study of human dependence on inactive mobile devices

The development of mobile phones has largely increased human interactions. Whilst the use of these devices for communication has received significant attention, there has been little analysis of more passive interactions. Through census data on casual social groups, this work suggests a clear pattern of mobile phones being carried in people’s hands, without the person using it (that is, not looking at it). Moreover, this study suggests that when individuals join members of the opposite sex there is a clear tendency to stop holding mobile phones whilst walking. Although it is not clear why people hold their phones whilst walking in such large proportions (38% of solitary women, and 31% of solitary men), we highlight several possible explanation for holding the device, including the need to advertise status and affluence, to maintain immediate connection with friends and family, and to mitigate feelings related to anxiety and security.

Women's attractiveness is linked to expected age at menopause

A great number of studies have shown that features linked to immediate fertility explain a large part of the variance in female attractiveness. This is consistent with an evolutionary perspective, as men are expected to prefer females at the age at which fertility peaks (at least for short-term relationships) in order to increase their reproductive success. However, for long-term relationships, a high residual reproductive value (the expected future reproductive output, linked to age at menopause) becomes relevant as well. In that case, young age and late menopause are expected to be preferred by men. However, the extent to which facial features provide cues to the likely age at menopause has never been investigated so far. Here, we show that expected age at menopause is linked to facial attractiveness of young women. As age at menopause is heritable, we used the mother's age at menopause as a proxy for her daughter's expected age of menopause. We found that men judged faces of women with a later expected age at menopause as more attractive than those of women with an earlier expected age at menopause. This result holds when age, cues of immediate fertility and facial ageing were controlled for. Additionally, we found that the expected age at menopause was not correlated with any of the other variables considered (including immediate fertility cues and facial ageing). Our results show the existence of a new correlate of women's facial attractiveness, expected age at menopause, which is independent of immediate fertility cues and facial ageing.

Facial Contrast Is a Cross-Cultural Cue for Perceiving Age

Age is a fundamental social dimension and a youthful appearance is of importance for many individuals, perhaps because it is a relevant predictor of aspects of health, facial attractiveness and general well-being. We recently showed that facial contrast-the color and luminance difference between facial features and the surrounding skin-is age-related and a cue to age perception of Caucasian women. Specifically, aspects of facial contrast decrease with age in Caucasian women, and Caucasian female faces with higher contrast look younger (Porcheron et al., 2013). Here we investigated faces of other ethnic groups and raters of other cultures to see whether facial contrast is a cross-cultural youth-related attribute. Using large sets of full face color photographs of Chinese, Latin American and black South African women aged 20-80, we measured the luminance and color contrast between the facial features (the eyes, the lips, and the brows) and the surrounding skin. Most aspects of facial contrast that were previously found to decrease with age in Caucasian women were also found to decrease with age in the other ethnic groups. Though the overall pattern of changes with age was common to all women, there were also some differences between the groups. In a separate study, individual faces of the 4 ethnic groups were perceived younger by French and Chinese participants when the aspects of facial contrast that vary with age in the majority of faces were artificially increased, but older when they were artificially decreased. Altogether these findings indicate that facial contrast is a cross-cultural cue to youthfulness. Because cosmetics were shown to enhance facial contrast, this work provides some support for the notion that a universal function of cosmetics is to make female faces look younger.

Age-Variation Face Recognition Based on Bayes Inference

Studies have discovered that face recognition will benefit from age information. However, since the age estimation is unstable in practice, it is still an open question how to improve face recognition with help of automatic age estimation techniques. This paper presents to improve the performance of face recognition by automatic age estimation. The main contribution is a new age-variational face recognition algorithm based on Bayesian framework (FRAB). By introducing the age estimation result as a prior, the recognition problem is divided into several age-specific sub-problems. As a result, the proposed algorithm leads to two algorithms according to how the age is given. The first one is FRAB-AE, which introduces age estimation result as the age prior. The second one is FRAB-GT, which considers that the ground truth of age information is given. Experimental results are conducted on FG-NET and Morph datasets to evaluate the performance of the proposed framework. It shows that the proposed algorithms is able to make use of age priors to improve the face recognition.

Anchoring in Numeric Judgments of Visual Stimuli

This article investigates effects of anchoring in age estimation and estimation of quantities, two tasks which to different extents are based on visual stimuli. The results are compared to anchoring in answers to classic general knowledge questions that rely on semantic knowledge. Cognitive load was manipulated to explore possible differences between domains. Effects of source credibility, manipulated by differing instructions regarding the selection of anchor values (no information regarding anchor selection, information that the anchors are randomly generated or information that the anchors are answers from an expert) on anchoring were also investigated. Effects of anchoring were large for all types of judgments but were not affected by cognitive load or by source credibility in either one of the researched domains. A main effect of cognitive load on quantity estimations and main effects of source credibility in the two visually based domains indicate that the manipulations were efficient. Implications for theoretical explanations of anchoring are discussed. In particular, because anchoring did not interact with cognitive load, the results imply that the process behind anchoring in visual tasks is predominantly automatic and unconscious.

Validation of the Amsterdam Dynamic Facial Expression Set--Bath Intensity Variations (ADFES-BIV): A Set of Videos Expressing Low, Intermediate, and High Intensity Emotions

Most of the existing sets of facial expressions of emotion contain static photographs. While increasing demand for stimuli with enhanced ecological validity in facial emotion recognition research has led to the development of video stimuli, these typically involve full-blown (apex) expressions. However, variations of intensity in emotional facial expressions occur in real life social interactions, with low intensity expressions of emotions frequently occurring. The current study therefore developed and validated a set of video stimuli portraying three levels of intensity of emotional expressions, from low to high intensity. The videos were adapted from the Amsterdam Dynamic Facial Expression Set (ADFES) and termed the Bath Intensity Variations (ADFES-BIV). A healthy sample of 92 people recruited from the University of Bath community (41 male, 51 female) completed a facial emotion recognition task including expressions of 6 basic emotions (anger, happiness, disgust, fear, surprise, sadness) and 3 complex emotions (contempt, embarrassment, pride) that were expressed at three different intensities of expression and neutral. Accuracy scores (raw and unbiased (Hu) hit rates) were calculated, as well as response times. Accuracy rates above chance level of responding were found for all emotion categories, producing an overall raw hit rate of 69% for the ADFES-BIV. The three intensity levels were validated as distinct categories, with higher accuracies and faster responses to high intensity expressions than intermediate intensity expressions, which had higher accuracies and faster responses than low intensity expressions. To further validate the intensities, a second study with standardised display times was conducted replicating this pattern. The ADFES-BIV has greater ecological validity than many other emotion stimulus sets and allows for versatile applications in emotion research. It can be retrieved free of charge for research purposes from the corresponding author.

Alcohol Sales to Youth: Data from Rural Communities Within the Cherokee Nation

Access to alcohol among individuals under 21 years of age continues to be a public health concern with approximately 5000 youth deaths attributable to alcohol each year (US Department of Health and Human Services 2007). To date, there is no research on youth access to alcohol from commercial sources within rural communities with large populations of Native American families. We evaluated commercial access to alcohol by underage-appearing female confederates in 4 rural towns within the Cherokee Nation, a non-reservation tribal jurisdiction that includes a high proportion of Native Americans embedded within a predominately White population. Alcohol purchase attempts were conducted approximately every 4 weeks on 10 occasions for a total of 997 alcohol purchase attempts. In addition to purchase attempt outcome, we collected data on characteristics of the outlets and clerks. Alcohol was sold to confederates without use of age identification on 23 % of all purchase attempts. Across repeated attempts, 76 % of outlets sold alcohol to a confederate at least once. Males and younger clerks were more likely to sell alcohol to the confederates. Grocery stores and gas stations were more likely to sell alcohol to the confederate than liquor stores, but this effect was no longer significant once seller age was accounted for in a multivariable model. Three out of 4 outlets sold alcohol to young-appearing buyers at least once across repeated attempts. Results reinforce the continuing need for regular enforcement of laws against selling alcohol to minors.

Examining the Effect of Smile Intensity on Age Perceptions

Research has demonstrated the positive effects of smiles on interpersonal perceptions of attractiveness, likability, and friendliness. A possible mechanism underlying the effects of smiles is babyfacedness. Four studies were conducted with 1,235 participants. In Study 1, 646 participants were assigned to one of the six levels of smile intensity and responded to the measures of age perception and perceived babyfacedness. Compared to the neutral expression, the maximal smile reduced age estimations and this effect was mediated by perceived babyfacedness. In Study 2, 59 respondents' responses indicated that a maximal smile reduced the perception of age. In Study 3, 318 respondents estimated the age of models in different sex and levels of smile intensity. Maximal smiles reduced age estimations. In Study 4, 125 students and 87 non-students were randomly assigned to one of the three levels of smile intensity and provided age estimations. Replicating previous findings, maximal smiles reduced age estimations. Consistent results emerged from the various contexts, models, and samples, as well as in a pooled analysis.

Can you hear my age? Influences of speech rate and speech spontaneity on estimation of speaker age

Cognitive hearing science is mainly about the study of how cognitive factors contribute to speech comprehension, but cognitive factors also partake in speech processing to infer non-linguistic information from speech signals, such as the intentions of the talker and the speaker’s age. Here, we report two experiments on age estimation by “naïve” listeners. The aim was to study how speech rate influences estimation of speaker age by comparing the speakers’ natural speech rate with increased or decreased speech rate. In Experiment 1, listeners were presented with audio samples of read speech from three different speaker age groups (young, middle aged, and old adults). They estimated the speakers as younger when speech rate was faster than normal and as older when speech rate was slower than normal. This speech rate effect was slightly greater in magnitude for older (60–65 years) speakers in comparison with younger (20–25 years) speakers, suggesting that speech rate may gain greater importance as a perceptual age cue with increased speaker age. This pattern was more pronounced in Experiment 2, in which listeners estimated age from spontaneous speech. Faster speech rate was associated with lower age estimates, but only for older and middle aged (40–45 years) speakers. Taken together, speakers of all age groups were estimated as older when speech rate decreased, except for the youngest speakers in Experiment 2. The absence of a linear speech rate effect in estimates of younger speakers, for spontaneous speech, implies that listeners use different age estimation strategies or cues (possibly vocabulary) depending on the age of the speaker and the spontaneity of the speech. Potential implications for forensic investigations and other applied domains are discussed.

Aging affects sex categorization of male and female faces in opposite ways

Faces are rich in social information; they easily give away a person's sex, approximate age, feelings, or focus of attention. Past research has mostly focused on investigating the distinct facial signals and perceptual mechanisms that allow us to categorize faces on these individual dimensions. It is less well understood how the different kinds of facial information interact. Here we investigated how the age of a face affects the ease with which young and older adults categorize its sex. Disconfirming everyday intuition, we showed that sex categorization is not generally hampered for older faces. Although categorization of female faces took progressively more time with increasing age, the opposite was found for male faces (Experiment 1). Differential effects of stimulus blurring and inversion for male and female faces of different ages (Experiment 2) strongly suggest one feature as a crucial mediator of the interdependence of age and sex perception - skin texture.

Demographic Estimation from Face Images: Human vs. Machine Performance

Demographic estimation entails automatic estimation of age, gender and race of a person from his face image, which has many potential applications ranging from forensics to social media. Automatic demographic estimation, particularly age estimation, remains a challenging problem because persons belonging to the same demographic group can be vastly different in their facial appearances due to intrinsic and extrinsic factors. In this paper, we present a generic framework for automatic demographic (age, gender and race) estimation. Given a face image, we first extract demographic informative features via a boosting algorithm, and then employ a hierarchical approach consisting of between-group classification, and within-group regression. Quality assessment is also developed to identify low-quality face images that are difficult to obtain reliable demographic estimates. Experimental results on a diverse set of face image databases, FG-NET (1K images), FERET (3K images), MORPH II (75K images), PCSO (100K images), and a subset of LFW (4K images), show that the proposed approach has superior performance compared to the state of the art. Finally, we use crowdsourcing to study the human perception ability of estimating demographics from face images. A side-by-side comparison of the demographic estimates from crowdsourced data and the proposed algorithm provides a number of insights into this challenging problem.

The effects of a culturally gender-specifying peripheral cue (headscarf) on the categorization of faces by gender

Faces convey a wealth of cues that influence social categorizations and subsequent cognition and behavior. This study examined the effects of wearing a headscarf on face categorization by gender using Egyptian observers who have an extensive exposure with headscarf-framed female faces. A typical headscarf (worn by females) enhanced perceived femininity whereas an atypical headscarf (worn by males) reduced perceived masculinity. Regardless of whether the faces were presented briefly, or until participants responded, the typical headscarf had no effect on categorizing female faces but the atypical headscarf greatly slowed down categorizing male faces. However, a typical headscarf advantage was noticed when the atypical headscarf condition was removed. In addition, both typical and atypical headscarf effects were greatly strengthened when faces were presented as negatives. These data provide support to the dynamic continuity account of social categorization that suggests a competition among multiple simultaneous representations until a construal is stabilized.

Aging Affects Identification of Vocal Emotions in Semantically Neutral Sentences

PURPOSE

The authors determined the accuracy of younger and older adults in identifying vocal emotions using the Toronto Emotional Speech Set (TESS; Dupuis & Pichora-Fuller, 2010a) and investigated the possible contributions of auditory acuity and suprathreshold processing to emotion identification accuracy.

METHOD

In 2 experiments, younger and older adults with normal hearing listened to and identified vocal emotions in the TESS stimuli. The TESS consists of phrases with controlled syntactic, lexical, and phonological properties spoken by an older female talker and a younger female talker to convey 7 emotion conditions (anger, disgust, fear, sadness, neutral, happiness, and pleasant surprise). Participants in both experiments completed audiometric testing; participants in Experiment 2 also completed 3 tests of suprathreshold auditory processing.

RESULTS

Identification by both age groups was above chance for all emotions. Accuracy was lower for older adults in both experiments. The pattern of results was similar across age groups and experiments. Auditory acuity did not predict identification accuracy for either age group in either experiment, nor did performance on tests of auditory processing in Experiment 2.

CONCLUSIONS

These results replicate and extend previous findings concerning age-related differences in ability to identify vocal emotions and suggest that older adults' auditory abilities do not explain their difficulties in identifying vocal emotions.

Fourier power spectrum characteristics of face photographs: attractiveness perception depends on low-level image properties

We investigated whether low-level processed image properties that are shared by natural scenes and artworks - but not veridical face photographs - affect the perception of facial attractiveness and age. Specifically, we considered the slope of the radially averaged Fourier power spectrum in a log-log plot. This slope is a measure of the distribution of special frequency power in an image. Images of natural scenes and artworks possess - compared to face images - a relatively shallow slope (i.e., increased high spatial frequency power). Since aesthetic perception might be based on the efficient processing of images with natural scene statistics, we assumed that the perception of facial attractiveness might also be affected by these properties. We calculated Fourier slope and other beauty-associated measurements in face images and correlated them with ratings of attractiveness and age of the depicted persons (Study 1). We found that Fourier slope - in contrast to the other tested image properties - did not predict attractiveness ratings when we controlled for age. In Study 2A, we overlaid face images with random-phase patterns with different statistics. Patterns with a slope similar to those in natural scenes and artworks resulted in lower attractiveness and higher age ratings. In Studies 2B and 2C, we directly manipulated the Fourier slope of face images and found that images with shallower slopes were rated as more attractive. Additionally, attractiveness of unaltered faces was affected by the Fourier slope of a random-phase background (Study 3). Faces in front of backgrounds with statistics similar to natural scenes and faces were rated as more attractive. We conclude that facial attractiveness ratings are affected by specific image properties. An explanation might be the efficient coding hypothesis.

Face recognition in schizophrenia disorder: A comprehensive review of behavioral, neuroimaging and neurophysiological studies

Facial emotion processing has been extensively studied in schizophrenia patients while general face processing has received less attention. The already published reviews do not address the current scientific literature in a complete manner. Therefore, here we tried to answer some questions that remain to be clarified, particularly: are the non-emotional aspects of facial processing in fact impaired in schizophrenia patients? At the behavioral level, our key conclusions are that visual perception deficit in schizophrenia patients: are not specific to faces; are most often present when the cognitive (e.g. attention) and perceptual demands of the tasks are important; and seems to worsen with the illness chronification. Although, currently evidence suggests impaired second order configural processing, more studies are necessary to determine whether or not holistic processing is impaired in schizophrenia patients. Neural and neurophysiological evidence suggests impaired earlier levels of visual processing, which might involve the deficits in interaction of the magnocellular and parvocellular pathways impacting on further processing. These deficits seem to be present even before the disorder out-set. Although evidence suggests that this deficit may be not specific to faces, further evidence on this question is necessary, in particularly more ecological studies including context and body processing.

Human height is positively related to interpersonal dominance in dyadic interactions

Across cultures, taller stature is linked to increased social status, but the potential reasons why this should be are unclear. One potential explanation is that taller individuals are more likely to win a dyadic confrontation with a competitor (i.e., they are more dominant), which leads to higher social rank. Although some previous studies have shown that perceptions of status or dominance are related to height, and are therefore consistent with such an explanation, there is surprisingly little research testing whether height actually has any influence on the behavioural outcomes in real-life social interactions. Here, we present three naturalistic observational studies demonstrating that height predicts interpersonal dominance during brief dyadic interactions. Study 1 investigated the likelihood of giving way in a narrow passage (N = 92); Study 2 investigated giving way in a busy shopping street, plus the likelihood of colliding with another individual (N = 1,108); and Study 3 investigated the likelihood of maintaining a linear path while walking, and potentially entering another individual’s personal space (N = 1,056). We conclude that human height is positively related to interpersonal dominance, and may well contribute to the widely observed positive association between height and social status.

Recognizing age-separated face images: humans and machines

Humans utilize facial appearance, gender, expression, aging pattern, and other ancillary information to recognize individuals. It is interesting to observe how humans perceive facial age. Analyzing these properties can help in understanding the phenomenon of facial aging and incorporating the findings can help in designing effective algorithms. Such a study has two components--facial age estimation and age-separated face recognition. Age estimation involves predicting the age of an individual given his/her facial image. On the other hand, age-separated face recognition consists of recognizing an individual given his/her age-separated images. In this research, we investigate which facial cues are utilized by humans for estimating the age of people belonging to various age groups along with analyzing the effect of one's gender, age, and ethnicity on age estimation skills. We also analyze how various facial regions such as binocular and mouth regions influence age estimation and recognition capabilities. Finally, we propose an age-invariant face recognition algorithm that incorporates the knowledge learned from these observations. Key observations of our research are: (1) the age group of newborns and toddlers is easiest to estimate, (2) gender and ethnicity do not affect the judgment of age group estimation, (3) face as a global feature, is essential to achieve good performance in age-separated face recognition, and (4) the proposed algorithm yields improved recognition performance compared to existing algorithms and also outperforms a commercial system in the young image as probe scenario.

Software-based evaluation of human age: a pilot study

PURPOSE

This pilot study was to assess a smartphone application regarding its use as an objective evaluation tool for subject age in comparison to human raters and to identify potential factors influencing the estimation of age.

MATERIALS AND METHODS

Ten Caucasian participants (six females, four males, mean age 42.1 ± 22.6 years) were randomly chosen, and frontal facial pictures of each participant were taken. The smartphone application PhotoAge (Version 1.5, ©2012, Percipo Inc., San Francisco, CA, USA) was used to evaluate the age of the participants. For comparison, 100 randomly selected raters (60 females, 40 males, mean age 29.3 ± 1.3 years) were asked to evaluate the age of the same participants. The influence of participants' facial expression, age, and sex as well as raters' age, sex, and profession was investigated as well. Statistical analyses (linear mixed models with random intercepts; least square means, confidence interval 95%; p < 0.05) were implemented.

RESULTS

PhotoAge resulted in a mean age of 43.1 ± 18.2 years, with a difference from the true mean age of 1.0 ± 8.2 years (p = 0.5996). The evaluation by the raters revealed a mean age of 41.5 ± 19.0 years, with a difference from the true mean age of -0.6 ± 8.5 years (p = 0.6078). There was no statistical significance between the two groups (p = 0.2783).

CONCLUSION

The evaluation of age with the software application PhotoAge seems to be a reliable procedure with comparable results to human raters.

CLINICAL SIGNIFICANCE

This study gives a better understanding about the reliability of a software-based evaluation tool for age and identifies factors (e.g., the visibility of the teeth) potentially affecting the estimation of age. Naturally looking teeth seem to have no influence on the evaluation of a person's age. Thus, the application of this specific application for dental purposes is questionable; however, in forensics, it might be a valuable tool for estimating a person's age.

With age comes representational wisdom in social signals

In an increasingly aging society, age has become a foundational dimension of social grouping broadly targeted by advertising and governmental policies. However, perception of old age induces mainly strong negative social biases [1, 2, 3]. To characterize their cognitive and perceptual foundations, we modeled the mental representations of faces associated with three age groups (young age, middle age, and old age), in younger and older participants. We then validated the accuracy of each mental representation of age with independent validators. Using statistical image processing, we identified the features of mental representations that predict perceived age. Here, we show that whereas younger people mentally dichotomize aging into two groups, themselves (younger) and others (older), older participants faithfully represent the features of young age, middle age, and old age, with richer representations of all considered ages. Our results demonstrate that, contrary to popular public belief, older minds depict socially relevant information more accurately than their younger counterparts.

Video Abstract

•

We model mental representations of age in young and old participants

•

Young participants dichotomize age into young (like them) and old (everyone else)

•

Old participants faithfully represent visual features of aging

•

Inhomogeneous dark marking in the skin around the nose predicts perceived age

I can't take my eyes off of you: attentional allocation to infant, child, adolescent and adult faces in mothers and non-mothers

It has been reported previously that infant faces elicit enhanced attentional allocation compared to adult faces in adult women, particularly when these faces are emotional and when the participants are mothers, as compared to non-mothers [1]. However, it remains unclear whether this increased salience of infant faces as compared to adult faces extends to children older than infant age, or whether infant faces have a unique capacity to elicit preferential attentional allocation compared to juvenile or adult faces. Therefore, this study investigated attentional allocation to a variety of different aged faces (infants, pre-adolescent children, adolescents, and adults) in 84 adult women, 39 of whom were mothers. Consistent with previous findings, infant faces were found to elicit greater attentional engagement compared to pre-adolescent, adolescent, or adult faces, particularly when the infants displayed distress; again, this effect was more pronounced in mothers compared to non-mothers. Pre-adolescent child faces were also found to elicit greater attentional engagement compared to adolescent and adult faces, but only when they displayed distress. No preferential attentional allocation was observed for adolescent compared to adult faces. These findings indicate that cues potentially signalling vulnerability, specifically age and sad affect, interact to engage attention. They point to a potentially important mechanism, which helps facilitate caregiving behaviour.

Category-specific face prototypes are emerging, but not yet mature, in 5-year-old children

Adults' expertise in face recognition has been attributed to norm-based coding. Moreover, adults possess separable norms for a variety of face categories (e.g., race, sex, age) that appear to enhance recognition by reducing redundancy in the information shared by faces and ensuring that only relevant dimensions are used to encode faces from a given category. Although 5-year-old children process own-race faces using norm-based coding, little is known about the organization and refinement of their face space. The current study investigated whether 5-year-olds rely on category-specific norms and whether experience facilitates the development of dissociable face prototypes. In Experiment 1, we examined whether Chinese 5-year-olds show race-contingent opposing aftereffects and the extent to which aftereffects transfer across face race among Caucasian and Chinese 5-year-olds. Both participant races showed partial transfer of aftereffects across face race; however, there was no evidence for race-contingent opposing aftereffects. To examine whether experience facilitates the development of category-specific prototypes, we investigated whether race-contingent aftereffects are present among Caucasian 5-year-olds with abundant exposure to Chinese faces (Experiment 2) and then tested separate groups of 5-year-olds with two other categories with which they have considerable experience: sex (male/female faces) and age (adult/child faces) (Experiment 3). Across all three categories, 5-year-olds showed no category-contingent opposing aftereffects. These results demonstrate that 5 years of age is a stage characterized by minimal separation in the norms and associated coding dimensions used for faces from different categories and suggest that refinement of the mechanisms that underlie expert face processing occurs throughout childhood.