Asymmetrical responding to male versus female other-race categories in 9- to 12-month-old infants

Faces can be categorized along various dimensions including gender or race, an ability developing in infancy. Infant categorization studies have focused on facial attributes in isolation, but the interaction between these attributes remains poorly understood. Experiment 1 examined gender categorization of other-race faces in 9- and 12-month-old White infants. Nine- and 12-month-olds were familiarized with Asian male or female faces, and tested with a novel exemplar from the familiarized category paired with a novel exemplar from a novel category. Both age groups showed novel category preferences for novel Asian female faces after familiarization with Asian male faces, but showed no novel category preference for novel Asian male faces after familiarization with Asian female faces. This categorization asymmetry was not due to a spontaneous preference hindering novel category reaction (Experiment 2), and both age groups displayed difficulty discriminating among male, but not female, other-race faces (Experiment 3). These results indicate that category formation for male other-race faces is mediated by categorical perception. Overall, the findings suggest that even by 12 months of age, infants are not fully able to form gender category representations of other-race faces, responding categorically to male, but not female, other-race faces.     

Learning unfamiliar faces in infants: The advantage of the regular sequence presentation and the three‐quarter view superiority

We investigated the effect of the regular sequence of different views and the three‐quarter view effect on the learning of unfamiliar faces by infants. 3–8‐month‐old infants were familiarized with unfamiliar female faces in either the regular condition (presenting 11 different face views from the frontal view to the left‐side profile view in regular order) or the random condition (presenting the same 11 different face views in random order). Following the familiarization, infants were tested with a pair of a familiarized and a novel female face either in a three‐quarter (Experiment 1) or in a profile view (Experiment 2). Results showed that only 6–8‐month‐old infants could identify a familiarized face in the regular condition when they were tested in three‐quarter views. In contrast, 6–8‐month‐old infants showed no significant novelty preference in profile views. The results suggest that the regular sequence of different face views promotes the learning of unfamiliar faces by infants over 6 months old. Moreover, our findings imply that the three‐quarter view effect appears in infants.     

Gender is a dimension of face recognition

In an experiment, the authors investigated the impact of gender categorization on face recognition. Participants were familiarized with composite androgynous faces labeled with either a woman's first name (Mary) or a man's first name (John). The results indicated that participants more quickly eliminated faces of the opposite gender than faces of the same gender than the face they were looking for. This gender effect did not result from greater similarity between faces of the same gender. Rather, early gender categorization of a face during face recognition appears to speed up the comparison process between the perceptual input and the facial representation. Implications for face recognition models are discussed.     

Female face preference in 4-month-olds: The importance of hairline

At 3–4 months of age, infants respond to gender information in human faces. Specifically, young infants display a visual preference toward female over male faces. In three experiments, using a visual preference task, we investigated the role of hairline information in this bias. In Experiment 1, we presented male and female composite faces with similar hairstyles to 4-month-olds and observed a preference for female faces. In Experiment 2, the faces were presented, but in this instance, without hairline cues, and the preference was eliminated. In Experiment 3, using the same cropping to eliminate hairline cues, but with feminized female faces and masculinized male faces, infants’ preference toward female faces was still not in evidence. The findings show that hairline information is important in young infants’ preferential orientation toward female faces.     

Development of category formation for faces differing by age in 9‐ to 12‐month‐olds: An effect of experience with infant faces

We examined category formation for faces differing in age in 9‐ and 12‐month‐olds, and the influence of exposure to infant faces on such ability. Infants were familiarized with adult or infant faces, and then tested with a novel exemplar from the familiarized category paired with a novel exemplar from a novel category (Experiment 1). Both age groups formed discrete categories of adult and infant faces, but exposure to infant faces in everyday life did not modulate performance. The same task was conducted with child versus infant faces (Experiment 2). Whereas 9‐month‐olds preferred infant faces after familiarization with child faces, but not child faces after familiarization with infant faces, 12‐month‐olds formed discrete categories of child and infant faces. Moreover, more exposure to infant faces correlated with higher novel category preference scores when infants were familiarized with infant faces in 12‐month‐olds, but not 9‐month‐olds. The 9‐month‐old asymmetry did not reflect spontaneous preference for infant over child faces (Experiment 3). These findings indicate that 9‐ and 12‐month‐olds can form age‐based categories of faces. The ability of 12‐month‐olds to form separate child and infant categories suggests that they have a more exclusive representation of face age, one that may be influenced by prior experience with infant faces.     

Origins of a stereotype: categorization of facial attractiveness by 6-month-old infants

Like adults, young infants prefer attractive to unattractive faces (e.g. Langlois, Roggman, Casey, Ritter, Rieser‐Danner & Jenkins, 1987 ; Slater, von der Schulenburg, Brown, Badenoch, Butterworth, Parsons & Samuels, 1998 ). Older children and adults stereotype based on facial attractiveness ( Eagly, Ashmore, Makhijani & Longo, 1991 ; Langlois, Kalakanis, Rubenstein, Larson, Hallam & Smooth, 2000 ). How do preferences for attractive faces develop into stereotypes? Several theories of stereotyping posit that categorization of groups is necessary before positive and negative traits can become linked to the groups (e.g. Tajfel, Billig, Bundy & Flament, 1971 ; Zebrowitz‐McArthur, 1982 ). We investigated whether or not 6‐month‐old infants can categorize faces as attractive or unattractive. In Experiment 1, we familiarized infants to unattractive female faces; in Experiment 2, we familiarized infants to attractive female faces and tested both groups of infants on novel faces from the familiar or novel attractiveness category. Results showed that 6‐month‐olds categorized attractive and unattractive female faces into two different groups of faces. Experiments 3 and 4 confirmed that infants could discriminate among the faces used in Experiments 1 and 2, and therefore categorized the faces based on their similarities in attractiveness rather than because they could not differentiate among the faces. These findings suggest that categorization of facial attractiveness may underlie the development of the ‘beauty is good’ stereotype.     

Infant preference for female faces occurs for same‐ but not other‐race faces

There has been a recent surge of interest in the question of how infants respond to the social attributes of race and gender information in faces. This work has demonstrated that by 3 months of age, infants will respond preferentially to same‐race faces and faces depicting the gender of the primary caregiver. In the current study, we investigated emergence of the female face preference for same‐ versus other‐race faces to examine whether the determinants of preference for face gender and race are independent or interactive in young infants. In Expt 1, 3‐month‐old Caucasian infants displayed a preference for female over male faces when the faces were Caucasian, but not when the faces were Asian. In Expt 2, new‐born Caucasian infants did not demonstrate a preference for female over male faces for Caucasian faces. The results are discussed in terms of a face prototype that becomes progressively tuned as it is structured by the interaction of the gender and race of faces that are experienced during early development.     

Females excel at basic face perception

Females are generally better than males at recognizing facial emotions. However, it is not entirely clear whether and in what way females may also excel at non-affective face recognition. Here, we tested males and females on two perceptual face recognition tasks that involved only neutral expressions: detection and identity discrimination. On face detection (Experiment 1), females were significantly more accurate than males in detecting upright faces. This gender difference was reduced during inverted face detection, and not present during tree detection, suggesting that the magnitude of the gender difference for performance co-varies with the extent to which face processing mechanisms are involved. On facial identity discrimination (Experiment 2), females again outperformed males, particularly when face images were masked by visual noise, or the delay between comparison face images was extended from 0.5 to 3 s. These results reveal a female advantage in processing face-specific information and underscore the role of perceptual factors in socially relevant gender differences.     

How do rhesus monkeys (<Emphasis Type="Italic">Macaca mulatta</Emphasis>) scan faces in a visual paired comparison task?

When novel and familiar faces are viewed simultaneously, humans and monkeys show a preference for looking at the novel face. The facial features attended to in familiar and novel faces, were determined by analyzing the visual exploration patterns, or scanpaths, of four monkeys performing a visual paired comparison task. In this task, the viewer was first familiarized with an image and then it was presented simultaneously with a novel and the familiar image. A looking preference for the novel image indicated that the viewer recognized the familiar image and hence differentiates between the familiar and the novel images. Scanpaths and relative looking preference were compared for four types of images: (1) familiar and novel objects, (2) familiar and novel monkey faces with neutral expressions, (3) familiar and novel inverted monkey faces, and (4) faces from the same monkey with different facial expressions. Looking time was significantly longer for the novel face, whether it was neutral, expressing an emotion, or inverted. Monkeys did not show a preference, or an aversion, for looking at aggressive or affiliative facial expressions. The analysis of scanpaths indicated that the eyes were the most explored facial feature in all faces. When faces expressed emotions such as a fear grimace, then monkeys scanned features of the face, which contributed to the uniqueness of the expression. Inverted facial images were scanned similarly to upright images. Precise measurement of eye movements during the visual paired comparison task, allowed a novel and more quantitative assessment of the perceptual processes involved the spontaneous visual exploration of faces and facial expressions. These studies indicate that non-human primates carry out the visual analysis of complex images such as faces in a characteristic and quantifiable manner.     

Categorization,categorical perception,and asymmetry in infants’ representation of face race

The present study examined whether 6‐ and 9‐month‐old Caucasian infants could categorize faces according to race. In Experiment 1, infants were familiarized with different female faces from a common ethnic background (i.e. either Caucasian or Asian) and then tested with female faces from a novel race category. Nine‐month‐olds were able to form discrete categories of Caucasian and Asian faces. However, 6‐month‐olds did not form discrete categories of faces based on race. In Experiment 2, a second group of 6‐ and 9‐month‐olds was tested to determine whether they could discriminate between different faces from the same race category. Results showed that both age groups could only discriminate between different faces from the own‐race category of Caucasian faces. The findings of the two experiments taken together suggest that 9‐month‐olds formed a category of Caucasian faces that are further differentiated at the individual level. In contrast, although they could form a category of Asian faces, they could not discriminate between such other‐race faces. This asymmetry in category formation at 9 months (i.e. categorization of own‐race faces vs. categorical perception of other‐race faces) suggests that differential experience with own‐ and other‐race faces plays an important role in infants’ acquisition of face processing abilities.     

Holistic processing of shape cues in face identification: Evidence from face inversion,composite faces,and acquired prosopagnosia

According to a classical functional architecture of face processing (Bruce & Young, 1986), sex processing on faces is a parallel function to individual face recognition. One consequence of the model is thus that sex categorization on faces is not influenced by face familiarity. However, the behavioural and neuro-psychological evidences supporting this dissociation are yet equivocal. To test the independence between sex processing on faces and familiar face recognition, familiar (learned) faces were morphed with new faces, generating facial continua of visual similarity to familiar faces. First, a pilot experiment shown that subjects familiarized with one extreme of the face continuum roughly perceive one half of the continuum (60 to 100% of visual similarity to familiar faces) as made of familiar faces and the other part as unfamiliar. In the experiment proper, subjects were familiarized with faces and tested in a sex decision task made on faces at the different steps of the continua. Subjects were significantly quicker at telling the sex of faces perceived as familiar (60-100%), and the effect was not observed in a control (untrained) group. These results indicate that familiar face representations are activated before sex categorization is completed, and can facilitate this processing. The nature of the interaction between sex categorization on faces and familiar face recognition is discussed.     

Face-based categorization, context-based categorization, and distortions in the recollection of gender ambiguous faces

In three studies, we examined the impact of face-based and context-based categorization in the recollection of gender ambiguous faces. Gender ambiguous faces were created by morphing male and female source faces. In Study 1, the recollection of moderately ambiguous faces (i.e., 70% male-30% female faces and 70% female-30% male faces) was accentuated towards face distracters that were more typical of the spontaneous (i.e., face-based) categorization of these faces. In Study 2, the recollection of extremely ambiguous faces (50% male-50% female faces) was accentuated towards face distracters that were more typical of the gender category suggested by context cues attached to these faces prior to the face presentation. Study 3 relied on the same design as Study 2, but this time context cues were provided after face encoding. In line with predictions, no accentuation effect emerged under the latter conditions. The theoretical and practical implications of these findings are discussed.     

面孔熟悉度对面孔性别与表情相互作用的调节

对于面孔性别与表情的关系, 目前的理论尚不完善。而众多研究证据表明, 面孔熟悉度与面孔性别及表情的加工均有密切关系。本研究基于Garner范式考察了在不同面孔熟悉度下面孔性别与表情的相互关系。共包括4项实验：实验1, 面孔刺激的身份陌生且不重复, 刺激在Garner范式的控制组和正交组中均仅呈现一次, 面孔熟悉度低; 实验2, 除面孔刺激的身份重复外, 其余均同实验1, 面孔熟悉度中等; 实验3, 面孔刺激的身份陌生且不重复, 但分别在控制组和正交组中重复呈现多次, 面孔熟悉度高; 实验4, 通过面孔学习增加面孔的熟悉度, 以直接验证面孔熟悉度的增加对面孔性别与表情相互关系的影响。结果发现：对于陌生面孔, 表情单向影响面孔性别的加工; 随着面孔熟悉度的增加, 面孔性别与表情之间出现双向的影响。因此, 面孔熟悉度对面孔性别与表情的相互影响具有调节作用。     

Infants' Bimodal Perception of Gender

Two experiments were independently conducted in separate labs to determine whether infants are sensitive to intermodal information specifying gender across dynamic displays of faces and voices. In one study, 4- and 6-month-old infants were presented simultaneously with a single videotape of a male face and a female face accompanied by a single voice for two 2 min trials. In the second study 3 112 and 6 month olds were also presented videotapes of male and female faces accompanied by a single voice but for a series of short trials. Temporal synchrony between face and voice was controlled in both studies by presenting both male and female faces speaking in synchrony with a single soundtrack. In both experiments the 6 month olds showed evidence of matching faces and voices on the basis of gender. They significantly increased their looking to a face when the gender-appropriate voice was played. Four month olds gave evidence for matching the faces and voices based on gender information only on the second trial of Experiment 1, whereas the 3 and a half month olds failed to show any preferential looking.     

Brief daily exposures to Asian females reverses perceptual narrowing for Asian faces in Caucasian infants

Perceptual narrowing in the visual, auditory, and multisensory domains has its developmental origins during infancy. The current study shows that experimentally induced experience can reverse the effects of perceptual narrowing on infants' visual recognition memory of other-race faces. Caucasian 8- to 10-month-olds who could not discriminate between novel and familiarized Asian faces at the beginning of testing were given brief daily experience with Asian female faces in the experimental condition and Caucasian female faces in the control condition. At the end of 3 weeks, only infants who received daily experience with Asian females showed above-chance recognition of novel Asian female and male faces. Furthermore, infants in the experimental condition showed greater efficiency in learning novel Asian females compared with infants in the control condition. Thus, visual experience with a novel stimulus category can reverse the effects of perceptual narrowing during infancy via improved stimulus recognition and encoding.     

Infants attend to second-order relational properties of faces

Two experiments investigated whether 7-month-old infants attend to the spatial distance measurements relating internal features of the human face. A visual preference paradigm was used, in which two versions of the same female face (one either lengthened or shortened, and one nonmodified) were presented simultaneously. In Experiment 1, infants looked longer at the nonmodified faces, which were determined to match the average distance relationships found in a sample of faces drawn from the same population. Longer looking times for modified faces were found in Experiment 2, in which the nonmodified faces were unusually long and the modified faces conformed to average distance measurements. It is proposed that infants’ attention to the spatial relations of internal face features is an optimal tool for lifelong face recognition.     

Novelty and frequency as determinants of newborn preference

The debate over whether infants prefer a familiar stimulus over a novel stimulus has persisted for over 30 years, and there is evidence which supports both sides of the question. However, the research which supports the preference for the familiar uses different measures than that which supports the preference for novelty. In the first experiment, the preference for the familiar was tested by making one stimulus more familiar than the others presented. A target of a ‘familiar’ face was presented eight times more frequently than the other faces. During the experiment, the infants could choose at which face they looked and for how long. It was found that the infants significantly preferred the familiar face over any one of the novel faces, especially when the familiar face was presented first. Substituting auditory for visual stimuli, the second experiment was a replication of the first experiment. Consonant–vowel syllables were used instead of faces. Overall, 17 stimuli were used: one repeating ‘familiar’ sound, and 16 novel sounds. It was found that the infants significantly preferred the familiar sound over any of the novel sounds. As found in Experiment 1, the infants also had a greater preference for the familiar sound when it was presented first.     

Cross-gender perceptions of facial attributes and their relation to attractiveness: do we see them differently than they see us?

Examination of perceptions of human facial attributes revealed that individual attributes are similarly perceived by males and females. However, patterns of attribute interrelationships differ as a function of gender of the face. Undergraduate students (N = 280) rated pictures of 40 male or female Caucasians on 12 physical attributes (e.g., nose size, face width) and overall attractiveness. The four sets of attribute ratings (defined by rater gender and picture gender) were submitted to principal components analyses, and five-factor solutions were found for each condition (accounting for about 76% of the variance). Comparisons of the four component solutions using confirmatory factor procedures revealed that male and female raters share one factor structure when rating photographs of female faces and another factor structure when rating photographs of male faces. Multiple regression analyses revealed that the patterns of attribute interrelationships were not "perceptual units" in the perception of attractiveness, and that different "rules" are used to assess the attractiveness of male and female stimuli faces. The importance of these results for models of facial attractiveness and interfacial similarity judgements are discussed.     

Young infants readily use proximity to organize visual pattern information

Four experiments relying on novelty and spontaneous preference procedures were performed to determine whether 3-4-month-old infants utilize the Gestalt principle of proximity to organize visual pattern information. In Experiment 1, infants familiarized with arrays of elements that could be organized into either columns or rows were tested for their preference between vertical and horizontal bars. The infants preferred the novel organization of bars. Experiments 2 and 3 showed that the novelty preference could not be attributed to an a priori preference or an inability to discriminate between the elements comprising the patterns. Experiment 4 replicated the results of Experiment 1 in a bars --> elements version of the task, indicating that extended exposure is not necessary for infants to organize based on proximity. The results suggest that infants readily organize visual pattern information in accord with proximity. Implications of this finding for models of the ontogenesis and microgenesis of object perception in infants and adults are discussed.