The still-face effect in Chinese and Canadian 3- to 6-month-old infants

Still-face effect in domestic dogs: comparing untrained with trained and animal assisted interventions dogs

The still-face effect has been extensively studied in human infants and comprises the reduction in affiliative behaviors and increased stress that occurs after a sudden interruption of social interaction with a caregiver. Domestic dogs (Canis familiaris) are model candidates for showing this effect, as they form deep bonds with their owners and interspecific social interaction is reinforcing to them. The aim of these studies was to assess if companion dogs exhibit the still-face effect and whether prior experiences during ontogeny modulate this effect. To this end, Study 1 compared dogs with different levels of training (untrained, intermediate, and advanced), while Study 2 assessed dogs that participated in Animal Assisted Interventions (AAIs) and companion dogs (CDs). The procedure was carried out virtually and comprised three phases lasting 1 min: interaction, still-face (the owner turned suddenly indifferent), and reunion (the interaction was resumed). Dogs exhibited a decrease in proximity to and contact with the owner, as well as an increase in begging and stress behaviors during the still-face phase. Moreover, this was not observed in a control condition in which the interaction continued in the same way during all three phases, discarding alternative explanations for these changes. These results show that dogs experience a still-face effect in a similar way to infants, highlighting the value interspecific social interaction has for dogs. Nevertheless, the absence of differences according to their training level or participation in AAIs suggests this is a robust phenomenon, which appears to be less susceptible to the influences of ontogenetic experiences.

Multimodal Approach for Characterizing the Quality of Parent-Child Interaction: A Single Synchronization Source May Not Tell the Whole Story

The interaction between the parent and child is essential for the child's cognitive and emotional development and sets the path for future well-being. These interactions, starting from birth, are necessary for providing the sensory stimulation the child needs in the critical time window of brain development. The characterization of parent-child interactions is traditionally performed by human decoding. This approach is considered the leading and most accurate way of characterizing the quality of these interactions. However, the development of computational tools and especially the concept of parent-child synchronization opened up an additional source of data characterizing these interactions in an objective, less human-labor manner. Such sources include brain-to-brain, voice/speech, eye contact, motor, and heart-rate synchronization. However, can a single source synchronization dataset accurately represent parent-child interaction? Will attending to the same stimulation, often resulting in a higher brain-to-brain synchronization, be considered an interactive condition? In this perspective, we will try to convey a new concept of the child-parent interaction synchronization (CHIPS) matrix, which includes the different sources of signals generated during an interaction. Such a model may assist in explaining the source of interaction alterations in the case of child/parent developmental/emotional or sensory deficits and may open up new ways of assessing interventions and changes in parent-child interactions along development. We will discuss this interaction during one of the parent-child joint activities providing opportunities for interaction, i.e., storytelling.

Still-face redux: Infant responses to a classic and modified still-face paradigm in proximal and distal care cultures

Literature on infant emotion is dominated by research conducted in Western, industrialized societies where early socialization is characterized by face-to-face, vocal communication with caregivers. There is a dearth of knowledge of infant emotion in the context of social interaction outside of the visual and vocal modalities. In a three-population cross-cultural comparison, we used the still-face task to measure variation in behavior among infants from proximal care (practicing high levels of physical contact) communities in Bolivia and distal care (emphasizing vocal and visual interaction) communities in the U.S. and Fiji. In a modified version of the face-to-face still-face (FFSF), Study 1, infants in the U.S. and Fiji displayed the typical behavioral response to the still-face episode: increased negative affect and decreased social engagement, whereas infants in Bolivia showed no change. For tactile behavior, infants in Bolivia showed an increase in tactile self-stimulation from the interaction episode to the still-face episode, whereas U.S. infants showed no change. In Study 2, we created a novel body-to-body version of the still-face paradigm ("still-body") with infants in US and Bolivia, to mimic the near-constant physical contact Bolivian infants experience. The U.S. and Bolivian infant response was similar to Study 1: US infants showed decreased positive affect and increased negative affect and decreased social engagement from the interaction to the still-body episode and Bolivian infants showed no change. Notably, there were overall differences in infant behaviors between the two paradigms (FFSF and Still-Body). Infants in Bolivia and the U.S. showed increased positive facial affect during the FFSF paradigm in comparison with the Still-Body paradigm. Our results demonstrate the need for more globally representative developmental research and a broader approach to infant emotion and communication.

Patterns of regulatory behavior in the still-face paradigm at 3 months: A comparison of Brazilian and Portuguese infants

Three infant regulatory behavior patterns have been identified during the Face-to-Face Still-Face paradigm (FFSF) in prior research samples: a Social-Positive Oriented pattern (i.e., infants exhibit predominantly positive social engagement), a Distressed-Inconsolable pattern (i.e., infants display conspicuous negative affect that persists or increases across FFSF episodes), and a Self-Comfort Oriented pattern (e.g., infants primarily engage in self-comforting behaviors such as thumb-sucking). However, few studies have examined these patterns outside US and European countries or evaluated potential cross-country differences in these patterns. In this study, we compared the regulatory behavior patterns of 74 Brazilian and 124 Portuguese infants in the FFSF at 3 months of age, and evaluated their links to demographic and birth variables. The prevalence of the three regulatory patterns varied by country. The most frequent pattern in the Portuguese sample was the Social-Positive Oriented, followed by the Distressed-Inconsolable and the Self-Comfort Oriented. However, in the Brazilian sample, the Distressed-Inconsolable pattern was the most prevalent, followed by the Social-Positive Oriented and the Self-Comfort Oriented. Moreover, in the Brazilian sample, familial SES was higher among infants with a Social-Positive pattern whereas 1^st-minute Apgar scores were lower among Portuguese infants with a Distressed-Inconsolable Oriented pattern of regulatory behavior. In each sample, Social Positive pattern of regulatory behavior was associated with maternal sensitivity, Self-Comfort Oriented pattern of regulatory behavior with maternal control, and Distressed-Inconsolable pattern with maternal unresponsivity.

Still-face Effect in Dogs (Canis familiaris). A Pilot Study

The Still-face Paradigm has been widely used for the assessment of emotion regulation in infants, as well as for the study of the mother-child relationship. Given the close bond that dogs have with humans, the purpose of this research was to evaluate, through an exploratory descriptive study, the presence of the Still-face effect in dogs. To this end, a group of Beagle dogs were exposed to three one-minute phases in which first, an unknown experimenter interacted actively and positively with each dog (Interaction). Then, suddenly, she interrupted the interaction and remained passive, with a non-expressive face and without speaking or petting the dog (Still-face). Finally, the experimenter reestablished the interaction (Reunion). Our results showed a decrease in affiliative behaviors in dogs during the Still-face phase according to changes in the human's behavior, a pattern similar to the one previously found in infants. Contrary to expectations, no stress-related behaviors were shown during that phase. A carry-over effect was also observed in the Reunion phase. This study provides information about the human-dog interaction and the effects of its disruption on dogs' behaviors.

Infant affect response in the face-to-face still face among Chinese- and European American mother-infant dyads

Early face-to-face interactions with caregivers allow infants to learn how to express and exchange emotions with others. Within the field, however, the research regarding infant regulatory processes across cultures remains limited. The Double Face-to-Face Still Face (FFSF) paradigm provided an opportunity to examine infant affect in dyadic interactions with European American (EA, n = 54) and Chinese American (CA, n = 48) infants and caregivers. Consistent with our hypothesis that CA infants are less reactive than EA infants, CA infants in our study showed less negative and more neutral affect compared to EA infants. We also examined the number of infants who were unable to complete the full FFSF paradigm due to high levels of distress (e.g., 30-sec of sustained hard cries). Compared to EA infants, more CA infants were unable to complete the paradigm due to negative affect (e.g., sustained cries). Analyses showed an association between mothers' negative affect from the start of the paradigm with infant incompletion of the paradigm. These findings point to cultural differences in infant affect within the FFSF. As well, researchers should consider the characteristics of infants who do not complete the FFSF paradigm as they can provide meaningful data in understanding infant affect and regulation. Taken together, our findings suggest that the Double FFSF paradigm provides a reasonable threshold for distinguishing infants on their ability to regulate during a repeated social stressor.

Infant's gaze in a teasing task with an experimenter or parent: A naturalistic approach

We assessed infant's gaze in a teasing task in New York City public spaces. The task was administered to two different groups of 5- to 13-month-old infants. We used a between participants design across two studies. In Study 1 an experimenter administered the task to these infants (n = 79), whereas a parent did so in Study 2 (n = 79). The adult engaged the infant with a toy and then pulled it away to one side by counting to 7. A second trial to the other side was repeated. Infants passed the teasing task if they looked to the adult's face within the first 5 seconds after removing the toy in at least one trial. In Study 1, we found that infants looked to the experimenter's face after teasing by 7 months of age. In Study 2, infants did not show any significant gazes to the parent's face after teasing at any age. Most trained parents successfully administered the teasing task to their infant. A teasing game played by an adult stranger (e.g., experimenter) may be optimal to elicit infant's gaze in a naturalistic setting. Implications for developing cost-effective social-cognitive milestone measures in non-laboratory settings are discussed.

Effect of Maternal Distress on Perceptions of Infant Behavior May Differ in Chinese-American and European-American Mothers and Infants

OBJECTIVE

This study examined the associations between maternal distress (symptoms of depression and anxiety) and observer and maternal ratings of infant temperament in Chinese-American (CA) and European-American (EA) 4-month-old infants (N = 114 dyads).

METHODS

Maternal distress was obtained through self-reported symptoms of depression and anxiety. Mothers reported infant temperament (distress at limitations, soothability, and fear) through the short form of the Infant Behavior Questionnaire-Revised. To obtain observer-rated infant reactivity, infants were administered a battery of visual and auditory stimuli in the laboratory, in which infant behaviors (fret/cry, limb activity, and arching of the back) were coded.

RESULTS

Maternal distress accounted more for the maternal perception of her infant among EA mothers than among CA mothers, but the relation was only observed for soothability. Higher maternal distress was associated with maternal report of lower soothability for EA mothers. Observer-rated infant reactivity, but not maternal distress, was positively associated with EA and CA maternal report of distress at limitations. Observer-rated infant negativity was associated with somewhat higher ratings of infant fear for EA mothers, although this association for EA mothers was not significantly different from CA mothers.

CONCLUSIONS

Potential biases in maternal report of infant behavior due to effects from maternal distress may not be generalizable across cultures but may vary because of cultural norms for emotional experience and expectations for infant behavior. EA mothers' ratings of infant distress and soothability, but not fear, may be influenced by maternal distress.

The effect of mother-infant skin-to-skin contact on Ghanaian infants' response to the Still Face Task: Comparison between Ghanaian and Canadian mother-infant dyads

The effect of mother-infant skin-to-skin contact on Ghanaian infants' developing social expectations for maternal behavior was investigated. Infants with high and low mother-infant skin-to-skin contact experience in the infants' first month engaged with their mothers in a Still Face Task at 6 weeks of age. Infants with high skin-to-skin contact experience, but not those with low skin-to-skin contact experience, demonstrated the still face effect with their smiles. Infants with both high and low skin-to-skin contact experience demonstrated the still face effect with their visual attention. The behaviors of the Ghanaian infants and their mothers during the task were compared to archival evidence of Canadian mother-infant dyads' behaviors in skin-to-skin and control groups who engaged in the Still Face Task at the infant ages of 1 and 2 months. Similarities and differences between the behaviors of the mother-infant dyads in the two cultures were assessed.

Toddler affect with mothers and fathers: the importance of infant attachment

The present study examined the degree to which toddlers' affect at 20 months during the Parent Ignore Toddler Situation (PITS), a modified still-face paradigm, with mothers and fathers was predicted by attachment (12 and 14 months), temperamental negative reactivity (3, 5, 7, 12, and 14 months), and attachment X negative reactivity during infancy. Parents (N = 135) were predominantly Caucasian (90.3% of mothers and 87.4% of fathers). Results from multi-level models, controlling for baseline affect and current parent sensitivity, indicated several effects involving attachment, but not temperament. An Episode X Avoidant attachment interaction indicated that toddlers who were classified as avoidant with either parent during infancy showed a flattened pattern of positive affect across the PITS episodes compared with those classified as secure. In contrast, a Parent X Ambivalent attachment interaction indicated that toddler negative affect was higher when they had an ambivalent attachment with mothers but not fathers.

The effect of the still-face paradigm on infant behavior: A cross-cultural comparison between mothers and fathers

Most still-face paradigm (SFP) studies have been done in Western families with infant-mother dyads. The present study investigated the SFP pattern in 123 Dutch and 63 Chinese 4-month-old infants with mothers and fathers. The classic SFP effect was found for positive affect and gaze in both countries. For negative affect, Chinese infants showed a different SFP pattern than Dutch infants. With fathers, infants displayed a less pronounced SFP pattern for positive affect and an increase from the still face to the reunion for negative affect. Only a minority of infants showed the expected SFP pattern across episodes. Our findings support that infant emotion expression is influenced by parent gender and cultural context. An interesting avenue for further study is the exploration of the origins of within- and between-gender and culture differences in affective communication between parents and infants.

Regulation During the Second Year: Executive Function and Emotion Regulation Links to Joint Attention, Temperament, and Social Vulnerability in a Latin American Sample

Although a growing body of work has established developing regulatory abilities during the second year of life, more work is needed to better understand factors that influence this emerging control. The purpose of the present study was to examine regulation capacities in executive functions (i.e., EF or cognitive control) and emotion regulation (i.e., ER or control focused on modulating negative and sustaining positive emotions) in a Latin American sample, with a focus on how joint attention, social vulnerability, and temperament contribute to performance. Sixty Latin American dyads of mothers and children aged 18 to 24 months completed several EF tasks, a Still-Face Paradigm (SFP) to examine ER (Weinberg et al., 2008), and the Early Social Communication Scale to measure joint attention (Mundy et al., 2003). Parents completed the Early Childhood Behavior Questionnaire Very Short Form to measure temperament (ECBQ-VS, Putnam et al., 2010) and the Social Economic Level Scale (SES) from INDEC (2000). Results revealed the typical responses expected for toddlers of this age in these EF tasks and in the SFP. Also, we found associations between EF and ER and between non-verbal communication related to monitoring infants’ attention to objects (i.e., responding to joint attention) and initiation of pointing (e.g., pointing and showing of an object while the child alternates his gaze to an adult) with EF. Regarding social factors, family differences and type of housing contribute to regulation. For temperament, effortful control was associated with both regulatory capacities. Finally, only age predicted EF. These results suggest that many patterns regarding the development of these abilities are duplicated in the first months of life in a Latin American sample while further highlighting the importance of considering how the environment and the individual characteristics of infants may associate to these regulatory abilities, which is particularly relevant to developing public policies to promote their optimal development.

Autonomic nervous system functioning assessed during the Still-Face Paradigm: A meta-analysis and systematic review of methods, approach and findings

Animal and human research suggests that the development of the autonomic nervous system (ANS) is particularly sensitive to early parenting experiences. The Still-Face Paradigm (SFP), one of the most widely used measures to assess infant reactivity and emotional competence, evokes infant self-regulatory responses to parental interaction and disengagement. This systematic review of 33 peer-reviewed studies identifies patterns of parasympathetic (PNS) and sympathetic (SNS) nervous system activity demonstrated by infants under one year of age during the SFP and describes findings within the context of sample demographic characteristics, study methodologies, and analyses conducted. A meta-analysis of a subset of 14 studies with sufficient available respiratory sinus arrhythmia (RSA) data examined whether the SFP reliably elicited PNS withdrawal (RSA decrease) during parental disengagement or PNS recovery (RSA increase) during reunion, and whether results differed by socioeconomic status (SES). Across SES, the meta-analysis confirmed that RSA decreased during the still-face episode and increased during reunion. When studies were stratified by SES, low-SES or high-risk groups also showed RSA decreases during the still face episode but failed to show an increase in RSA during reunion. Few studies have examined SNS activity during the SFP to date, preventing conclusions in that domain. The review also identified multiple qualifications to patterns of SFP ANS findings, including those that differed by ethnicity, infant sex, parental sensitivity, and genetics. Strengths and weaknesses in the extant research that may explain some of the variation in findings across the literature are also discussed, and suggestions for strengthening future research are provided.

Assessment of Maternal-Infant Interaction: Application of the Still Face Paradigm in a Rural Population of Working Women in Ecuador

Objectives The importance of mother-child interaction in early infancy on child development has been well documented. The purpose of this study was to assess the feasibility of using the Still Face Paradigm to measure mother interactive style, infant affect and emotional regulation in a rural Ecuador setting. Methods Infant's emotional regulation and the quality of mother's interaction were measured with the Still Face Paradigm at 4 months of age (±15 days). Twenty-four infants and their mothers were assessed in their home. Mother interactive style was coded for attention seeking and contingent responding. Emotional regulation was described by change in infant affect between Still Face episodes. Results A significant difference was found for infant affect between the five Still Face episodes (F_1,118 = 9.185, p = 0.003). A significant negative correlation was found for infant affect between episode 3 and 2 with attention seeking mother interactive style during episode 3 (rho = -0.44, p = 0.03), indicating that mothers using more contingent-responding interactions had infants with more positive affect. Conversely, a significant positive association was found for infant affect between episode 3 and 2 and contingent responding mother interactive style during episode 3 (rho = 0.46, p = 0.02), indicating that mothers who used more attention seeking play had infants who showed less positive affect. Conclusion for Practice Study results demonstrate feasibility in using the Still Face Paradigm in working populations residing in a rural region in Ecuadorian highlands and may be feasible in other similar populations in Latin America, and as a successful approach to measuring maternal-child interactions within a field-based epidemiological study design.

Neonates' responses to repeated exposure to a still face

AIM

The main aims of the study were to examine whether human neonates' responses to communication disturbance modelled by the still-face paradigm were stable and whether their responses were affected by their previous experience with the still-face paradigm.

METHODS

The still face procedure, as a laboratory model of interpersonal stress, was administered repeatedly, twice, to 84 neonates (0 to 4 day olds), with a delay of an average of 1.25 day.

RESULTS

Frame-by-frame analysis of the frequency and duration of gaze, distressed face, crying, sleeping and sucking behaviours showed that the procedure was stressful to them both times, that is, the still face effect was stable after repeated administration and newborns consistently responded to such nonverbal violation of communication. They averted their gaze, showed distress and cried more during the still-face phase in both the first and the second administration. They also showed a carry-over effect in that they continued to avert their gaze and displayed increased distress and crying in the first reunion period, but their gaze behaviour changed with experience, in the second administration. While in the first administration the babies continued averting their gaze even after the stressful still-face phase was over, this carry-over effect disappeared in the second administration, and the babies significantly increased their gaze following the still-face phase.

CONCLUSION

After excluding explanations of fatigue, habituation and random effects, a self-other regulatory model is discussed as a possible explanation for this pattern.

Affect and maternal parenting as predictors of adaptive and maladaptive behaviors in Chinese children

Emotional control has traditionally been emphasized in Chinese culture. The primary purpose of the study was to examine the relevance of early affect to social functioning in Chinese children. A sample of children, initially at two years of age, and their mothers in the People's Republic of China participated in this two-year longitudinal study. At Time 1, observational data were collected on children's affect and maternal parenting in mother-child interactions. At Time 2, children's behaviors were assessed in peer interactions. In addition, data on behavioral problems were collected from parental reports. It was found that whereas positive affect positively predicted prosocial behavior, negative affect was positively associated with later behavioral problems. Both positive and negative affects were negatively associated with on-task behaviors. Finally, child affect might moderate the relation between maternal parenting and social behaviors. The results indicate the role of child affect and parenting in social and behavioral development in Chinese context.

Post-institutionalized Chinese and Eastern European children: Heterogeneity in the development of emotion understanding

Post-institutionalized Chinese and Eastern European children participated in two emotion understanding tasks. In one task, children selected facial expressions corresponding to four emotion labels (happy, sad, angry, scared). The second task required children to match facial expressions to stories describing situations for these emotions. While both post-institutionalized groups scored lower than the never-institutionalized children, those from China performed better than those from Eastern Europe. Post-institutionalized children's performance was predicted by their age at adoption.

Face-to-face emotion interaction studies in Down syndrome infants

Infants with Down syndrome constitute an ideal population for analysing the development of emotional expression from the first months of life, due basically to the fact that this chromosomal alteration is identifiable from birth and results in well-known difficulties of cognitive development and in basic learning processes. Taking into account the functional aspects of facial expression during initial social interaction, in this review we present a series of studies which, although based on different theoretical approaches and different methodologies, have the common objective of analysing the emotional behaviour of young infants with and without Down syndrome during face-to-face interaction with their mothers. The main conclusions emerging from these studies are: (a) that, as in the case of typically developing infants, Down syndrome infants and their mothers present a series of coordinated and interdependent expressive interchanges; (b) that, despite the differences found between infants with and without Down syndrome in quantitative parameters of expressive behaviour, such as frequency, duration and intensity of the different emotional expressions or their point of initiation in development, what seems to be most significant is the clear functional similarity observed in the two groups of subjects during initial mother-infant interaction; and (c) that these differences may be understood by considering different psychobiological explanations as well as the known cognitive deficits.

Visual scanning and recognition of Chinese, Caucasian, and racially ambiguous faces: contributions from bottom-up facial physiognomic information and top-down knowledge of racial categories

Recent studies have shown that participants use different eye movement strategies when scanning own- and other-race faces. However, it is unclear (1) whether this effect is related to face recognition performance, and (2) to what extent this effect is influenced by top-down or bottom-up facial information. In the present study, Chinese participants performed a face recognition task with Chinese, Caucasian, and racially ambiguous faces. For the racially ambiguous faces, we led participants to believe that they were viewing either own-race Chinese faces or other-race Caucasian faces. Results showed that (1) Chinese participants scanned the nose of the true Chinese faces more than that of the true Caucasian faces, whereas they scanned the eyes of the Caucasian faces more than those of the Chinese faces; (2) they scanned the eyes, nose, and mouth equally for the ambiguous faces in the Chinese condition compared with those in the Caucasian condition; (3) when recognizing the true Chinese target faces, but not the true target Caucasian faces, the greater the fixation proportion on the nose, the faster the participants correctly recognized these faces. The same was true when racially ambiguous face stimuli were thought to be Chinese faces. These results provide the first evidence to show that (1) visual scanning patterns of faces are related to own-race face recognition response time, and (2) it is bottom-up facial physiognomic information that mainly contributes to face scanning. However, top-down knowledge of racial categories can influence the relationship between face scanning patterns and recognition response time.

Own- and other-race face scanning in infants: implications for perceptual narrowing

The present study investigated how 6- and 9-month-old Caucasian infants scan Caucasian and Chinese dynamic faces using eye-tracking methodology. Analyses of looking times revealed that with increased age, infants decreased their looking time to other-race noses, while maintaining their looking time for own-race noses. From 6 to 9 months, infants increased their looking time for the eyes of both races of faces. Analyses of scan paths showed that infants were no more likely to shift their fixation between the eyes of own-race faces than other-race faces. Similarity between participants' scan paths suggested that facial information was collected more efficiently for own- versus other-race faces at 9 months of age. Combined with previous eye-tracking studies of infants' face scanning (Liu et al. [2011] Journal of Experimental Child Psychology, 108, 180-189; Wheeler et al. [2011] PLoS ONE, 6, e18621. doi: 10.1371/journal.pone.0018621; Xiao et al. [2013] International Journal of Behavioral Development, 37, 100-105), the findings are interpreted in the context of perceptual narrowing and suggest differential contributions of visual experience, facial physiognomy, and culture in accounting for similarity and difference in infants scanning of own- and other-race faces.

Adults scan own- and other-race faces differently

It is well established that individuals show an other-race effect (ORE) in face recognition: they recognize own-race faces better than other-race faces. The present study tested the hypothesis that individuals would also scan own- and other-race faces differently. We asked Chinese participants to remember Chinese and Caucasian faces and we tested their memory of the faces over five testing blocks. The participants' eye movements were recorded with the use of an eye tracker. The data were analyzed with an Area of Interest approach using the key AOIs of a face (eyes, nose, and mouth). Also, we used the iMap toolbox to analyze the raw data of participants' fixation on each pixel of the entire face. Results from both types of analyses strongly supported the hypothesis. When viewing target Chinese or Caucasian faces, Chinese participants spent a significantly greater proportion of fixation time on the eyes of other-race Caucasian faces than the eyes of own-race Chinese faces. In contrast, they spent a significantly greater proportion of fixation time on the nose and mouth of Chinese faces than the nose and mouth of Caucasian faces. This pattern of differential fixation, for own- and other-race eyes and nose in particular, was consistent even as participants became increasingly familiar with the target faces of both races. The results could not be explained by the perceptual salience of the Chinese nose or Caucasian eyes because these features were not differentially salient across the races. Our results are discussed in terms of the facial morphological differences between Chinese and Caucasian faces and the enculturation of mutual gaze norms in East Asian cultures.

Caucasian infants scan own- and other-race faces differently

Young infants are known to prefer own-race faces to other race faces and recognize own-race faces better than other-race faces. However, it is entirely unclear as to whether infants also attend to different parts of own- and other-race faces differently, which may provide an important clue as to how and why the own-race face recognition advantage emerges so early. The present study used eye tracking methodology to investigate whether 6- to 10-month-old Caucasian infants (N = 37) have differential scanning patterns for dynamically displayed own- and other-race faces. We found that even though infants spent a similar amount of time looking at own- and other-race faces, with increased age, infants increasingly looked longer at the eyes of own-race faces and less at the mouths of own-race faces. These findings suggest experience-based tuning of the infant's face processing system to optimally process own-race faces that are different in physiognomy from other-race faces. In addition, the present results, taken together with recent own- and other-race eye tracking findings with infants and adults, provide strong support for an enculturation hypothesis that East Asians and Westerners may be socialized to scan faces differently due to each culture's conventions regarding mutual gaze during interpersonal communication.

Infant responses to maternal still-face at 4 and 9 months

This study investigated developmental changes in infant responses to maternal still-face (SF) situations. Infants (21 males and 25 females) of Japanese mothers were observed in a face-to-face SF paradigm, comprising four phases (normal/SF/normal/SF), at two infant ages (4 and 9 months). The infants' facial expression, gaze direction, and vocalization were coded in both SF and normal interaction conditions. The results indicated that infants at both ages showed a decrease in displaying positive facial expression and gazing at their mothers during SF conditions. The 4-month-old displayed emotional expression and directed their gaze toward their mothers more frequently than the 9-month-old. However, the 9-month-old vocalized more often in SF situations, attempting to elicit responses from their mothers. The "carry-over" effect was observed only in 9-month-old. The results were discussed in the context of developmental changes in infants' social skills to cope with an emotionally stressful situation.

Culture, ethnicity, and children's facial expressions: A study of European American, mainland Chinese, Chinese American, and adopted Chinese girls

This investigation extends previous research documenting differences in Chinese and European American infants' facial expressivity. Chinese girls adopted by European American families, nonadopted Mainland Chinese girls, nonadopted Chinese American girls, and nonadopted European American girls responded to emotionally evocative slides and an odor stimulus. European American girls smiled more than Mainland Chinese and Chinese American girls and scored higher than Mainland Chinese girls for disgust-related expressions and overall expressivity. Adopted Chinese girls produced more disgust-related expressions than Mainland Chinese girls. Self-reported maternal strictness, aggravation, positive expressiveness, and cultural identification correlated with children's facial responses, as did number of siblings and adults in the home. Results suggest that culture and family environment influences facial expressivity, creating differences among children of the same ethnicity.

Smiling of male and female infants to mother vs stranger at 2 and 3 months of age

The study examined the recognition-assimilation hypothesis of infant smiling. The subjects were 64 (32 female and 32 male) full-term infants who were visited at their home at ages two and three months by a female experimenter. The mother and then the female stranger each interacted face-to-face with the infants for 3 min. All interactions were videotaped and later independent coders recorded the cumulative amount of time that the infants smiled to the mother and to the stranger. The results show that, whereas female infants smiled significantly more to the stranger than to the mother at both ages, male infants smiled more to the mother only at two months. At three months, male infants smiled about the same length of time to both mother and stranger. The results support the recognition-assimilation hypothesis and suggest that females develop faster socially.