Differential Behavioural Effects of Silent Bared Teeth Display and Relaxed Open Mouth Display in Chimpanzees (Pan troglodytes)

This study examines the behavioural consequences of the silent bared teeth display (SBT) and the relaxed open mouth display (ROM) in the chimpanzee, and discusses functional similarities with smiling and laughing (respectively) in humans. Rates of affinitive behaviour increase (in relation to baseline levels) following SBT, suggesting that SBT is a signal of affinity. ROM is observed primarily during play, and dyadic play bouts are significantly longer when ROM is bidirectional, indicating that it may be a signal of play. Rates of affinitive behaviour also increased after ROM, suggesting that both displays may have a similar ultimate (evolutionary) function – social bonding; this could explain convergence of the two displays in humans.     

Social Behaviors Increase in Children with Autism in the Presence of Animals Compared to Toys

Background

Previous research has demonstrated the capacity of animal presence to stimulate social interaction among humans. The purpose of this study was to examine the interactions of children with autism spectrum disorder (ASD) with an adult and their typically-developing peers in the presence of animals (two guinea pigs) compared to toys.

Methods

Ninety-nine children from 15 classrooms in 4 schools met the inclusion criteria and participated in groups of three (1 child with ASD and 2 typically-developing peers). Each group was video-recorded during three 10-minute, free-play sessions with toys and three 10-minute, free-play sessions with two guinea pigs. Two blinded observers coded the behavior of children with ASD and their peers. To account for the nested study design, data were analyzed using hierarchical generalized linear modeling.

Results

Participants with ASD demonstrated more social approach behaviors (including talking, looking at faces, and making tactile contact) and received more social approaches from their peers in the presence of animals compared to toys. They also displayed more prosocial behaviors and positive affect (i.e., smiling and laughing) as well as less self-focused behaviors and negative affect (i.e., frowning, crying, and whining) in the presence of animals compared to toys.

Conclusions

These results suggest that the presence of an animal can significantly increase positive social behaviors among children with ASD.     

Sex differences in smiling and other photographed traits: a theoretical assessment

Many studies have shown that females smile more than males do in social situations. The present study extends this research by examining a large sample of high school yearbook photographs. In addition to assessing the degree of smiling, ratings were obtained of the following traits for each photograph: hair length, hair colour, masculine-feminine appearance and physical attractiveness. Results reconfirmed earlier research showing that females smile more than males do while they are being photographed. Other findings were that smiling was positively correlated with hair length, femininity and physical attractiveness for females but not for males. When a multivariate analysis was performed, none of these traits predicted smiling in males, and only femininity was significant in predicting smiling in females. Although social learning theories of smiling can account for some of these findings, a recently proposed neurohormonal theory seems to best explain why femininity is related to smiling in females but not in males.     

Interactions of mothers and nurses with premature infants.

The initial attachment of three mothers to three premature infants weighing less than 1500 g was assessed by observation of the mother''s behaviour during visits to her child in the hospital nursery. Interactions of mothers and infants were compared with those of nurses and infants. Premature infants, during a stay in hospital of approximately 7 weeks, have to adapt to up to 70 different nurses and receive generally little contact stimulation from them. Mothers change in their interactional behaviour over time but show persistent individual differences in amount of touching, smiling and talking to their infants. Follow-up investigation will determine if the maternal behaviour as demonstrated in the nursery is predictive of later parenting disorders.     

Social smiling in normal and down syndrome infants: A comparative study

The aim of this work has been to compare social smiling in Down syndrome (mongolism) and normal infants, attending especially to the brow movements that appear before it. Facial responses of eight Down syndrome and eight normal infants from three to five months were analized by means of an anatomically based measurement technique during face-to-face interactions with their mothers. Despite their mental retardation, Down syndrome infants showed identical muscle movements as normal infants before and during smiling. However, some differences were found in smile frequency and leght, as well as in the brow movements frequency before smiling. Results are discussed in terms of the psychophisiological dysfunction of Down syndrome infants that are originated by a chromosome imbalance.     

Forms and Social Signal Value of Smiles Associated with Pleasant and Unpleasant Sensory Experience

Episodes of facial displays involving the zygomatic action (AU12: lip corner pulling or smiling) were selected from a large sample of children (n = 95) exposed to pleasant and unpleasant odours in the presence of an unfamiliar person in order to investigate potential differences in morphological, temporal patterning and social signal value of smiling. In a first experiment, using the facial action coding system (FACS: Ekman & Friesen 1978), a considerable morphological flexibility of smiles was observed in relation to the subjects' hedonic experience. The facial configurations of smiling were formed by a number of actions in the upper (AU 4: brow lowering), middle (AU 9: nose wrinkling) and lower face (AU 14: dimpling, AU 15: lip comer depressing, AU 17: chin raising, AU 23: lip tightening) and the mouth was more often ‘closed’ in response to unpleasant odours. When exposed to pleasant odours, zygomatic action co-occurred more frequently with an opening of the mouth (AUs 25, 26, 27) or with a raising of the cheeks (AU 6). An analysis of the temporal patterning of zygomatic actions showed that they occurred more rapidly, dropped off the face less abruptly with a stepped decrease, were less smooth, and were often associated with shorter gazes directed toward the examiner in response only to unpleasant odours. These findings suggested that a number of subjects might exert some control on their smiling while confronted with a presumed social constraint, namely the smelling of unpleasant odours in the presence of an unfamiliar person. In a second experiment, the communicative value of smiling was investigated in a real-time projection of 10 variants of smiling to a panel of receivers (n = 52). The Duchenne smile (AU 6 + 12 + 25) and smile with lips opening (12 + 25) provided more accurate information about the hedonic valence of the inhaled odour than did the other types of smiling. In contrast, the perceived valence of the facial displays simultaneously combining zygomatic action with muscular actions of the lower face (AUs 15, 17, 23) appeared more difficult to discriminate by untrained receivers. It was hypothesized that the senders displayed some forms of smiling possibly to mask their responsiveness to unpleasant odours in signalling ambiguous or incorrect information about their internal state to a recipient.     

Positive Feeling,Negative Meaning: Visualizing the Mental Representations of In-Group and Out-Group Smiles

Even though smiles are seen as universal facial expressions, research shows that there exist various kinds of smiles (i.e., affiliative smiles, dominant smiles). Accordingly, we suggest that there also exist various mental representations of smiles. Which representation is employed in cognition may depend on social factors, such as the smiling person’s group membership: Since in-group members are typically seen as more benevolent than out-group members, in-group smiles should be associated with more benevolent social meaning than those conveyed by out-group members. We visualized in-group and out-group smiles with reverse correlation image classification. These visualizations indicated that mental representations of in-group smiles indeed express more benevolent social meaning than those of out-group smiles. The affective meaning of these visualized smiles was not influenced by group membership. Importantly, the effect occurred even though participants were not instructed to attend to the nature of the smile, pointing to an automatic association between group membership and intention.     

The effects of testosterone and estrogen on the rate of long-calling vocalization in juvenile laughing gulls, Larus atricilla.

The frequency of long-calling in untreated and hormone-treated juvenile laughing gulls was compared. While both estrogen and testosterone increased the calling rate, testosterone was more effective for both sexes. Both estrogen- and testosterone-treated males called more often than similarly treated females. As both sexes normally call in laughing gulls, these results were compared to the more usual situation where only males of the species sing. Possible control mechanisms were discussed.     

笑弧在面部宽窄不同的个体中对微笑美学的影响

目的:研究面部宽窄不同女性的笑弧对微笑美学的影响。方法:选取女性正位微笑像1张,应用Adobe Photoshop CS5软件对笑弧和面部宽窄进行修改,由正畸医生和非专业人士对照片的微笑魅力值进行评判。结果:笑弧和面部宽窄程度在魅力微笑的判别中无交互作用(P0.05)。两组对理想的笑弧、略窄的面型和适宜的面型的魅力微笑判别分值较高(P0.05)。非专业人群中,在三种笑弧中,除了很窄的面型,魅力微笑的分值均随着面型的增宽降低(P0.05)。专业人群中,对于平坦的笑弧,除了很宽的面型,魅力微笑的分值随着面型的增宽而增加(P0.05);对于理想的笑弧,魅力微笑的分值随着面型的过宽或过窄而降低,但仍高于其他两种笑弧(P0.05);对于弯曲的笑弧,除了很窄的面型,魅力微笑的分值随着面型的增宽而降低(P0.05)。结论:笑弧和面部宽窄对魅力微笑的判别具有一定影响。不同人群对笑弧及面部宽窄与微笑美学的认识也存在差异,在正畸治疗中应根据患者面部宽窄合理的选择治疗方案。     

白颊噪鹛四川亚种繁殖期鸣声声谱分析

2008年3～10月,在四川省南充市郊通过声谱分析对白颊噪鹛四川亚种Garrulax sannio oblectans繁殖期的鸣声与行为做了初步研究.其鸣声类型具有占区、驱赶、雌雄应答、求偶、交配、乞食、召唤、报警、惊叫及集群觅食等鸣声.其鸣声大多由短的重复的单音节、双音节和多音节鸣声组成.鸣声音节中最常见为单音节鸣声,最少的为多音节鸣声.     

Non-verbal communication of the residents living in homes for the older people in Slovenia

Aging of the population is a growing problem in all developed societies. The older people need more health and social services, and their life quality in there is getting more and more important. The study aimed at determining the characteristics of non-verbal communication of the older people living in old people's homes (OPH). The sample consisted of 267 residents of the OPH, aged 65-96 years, and 267 caregivers from randomly selected twenty-seven OPH. Three types of non-verbal communication were observed and analysed using univariate and multivariate statistical methods. In face expressions and head movements about 75% older people looked at the eyes of their caregivers, and about 60% were looking around, while laughing or pressing the lips together was rarely noticed. The differences between genders were not statistically significant while statistically significant differences among different age groups was observed in dropping the eyes (p = 0.004) and smiling (0.008). In hand gestures and trunk movements, majority of older people most often moved forwards and clenched fingers, while most rarely they stroked and caressed their caregivers. The differences between genders were statistically significant in leaning on the table (p = 0.001), and changing the position on the chair (0.013). Statistically significant differences among age groups were registered in leaning forwards (p = 0.006) and pointing to the others (p = 0.036). In different modes of speaking and paralinguistic signs almost 75% older people spoke normally, about 70% kept silent, while they rarely quarrelled. The differences between genders were not statistically significant while statistically significant differences among age groups was observed in persuasive speaking (p = 0.007). The present study showed that older people in OPH in Slovenia communicated significantly less frequently with hand gestures and trunk movements than with face expressions and head movements or different modes of speaking and paralinguistic signs. The caregivers should be aware of this and pay a lot of attention to these two groups of non-verbal expressions. Their importance should be constantly emphasized during the educational process of all kinds of health-care professionals as well.     

Conditions of observation and social distance in groups of squirrel monkeys,Saimiri sciureus

Observation conditions were very influential in determining the social distance among members of groups of squirrel monkeys. With observer visible to the animals and recording by talking into a tape recorder the monkeys did not show a consistent pattern of social distance as reflected by actual space and frequency of bodily contacts, whereas when the observer was concealed, looking through a one-way vision screen and recording silently by marking on paper, the subjects tended to group in unisexual clusters, with that of the females showing higher cohesiveness.     

Dynamically engaged smiling predicts cooperation above and beyond average smiling levels

Smiling has been conceptualized as a signal of cooperative intent, yet smiles are easy to fake. We suggest that contextually appropriate, dynamically engaged smiling imposes an attentional cost, thereby making engaged smiling a plausible “honest signal” of cooperative intent. To test this hypothesis, we analyzed data from 123 pairs of same-sex strangers having “getting-to-know-you” conversations who subsequently played a one-shot prisoner's dilemma together. We calculated the strength of engagement in smiling using a cross-lagged auto-regressive model for dyadic data. We found that when an individual's partner (the signaler) tended to smile in a more responsive way, that individual (the receiver) was more likely to cooperate. Conversely, when a signaler tended to smile in a less responsive way, the receiver was less likely to cooperate. These effects were present over-and-above the effects of average levels of smiling and self-reported liking, which also predicted likelihood of cooperation. However, dynamically engaged smiling did not predict cooperation on the part of the signaler, suggesting that receivers weight the importance of engagement more highly than they should, or even that engaged smiling might be a manipulative display. These results illustrate how conversational dynamics can influence evolutionary signaling.     

Social transmission of face preferences among humans

Previous studies demonstrating mate choice copying effects among females in non-human species have led many researchers to propose that social transmission of mate preferences may influence sexual selection for male traits. Although it has been suggested that social transmission may also influence mate preferences in humans, there is little empirical support for such effects. Here, we show that observing other women with smiling (i.e. positive) expressions looking at male faces increased women's preferences for those men to a greater extent than did observing women with neutral (i.e. relatively negative) expressions looking at male faces. By contrast, the reverse was true for male participants (i.e. observing women with neutral expressions looking at male faces increased male participant's preferences for those men to a greater extent than did observing women smiling at male faces). This latter finding suggests that within-sex competition promotes negative attitudes among men towards other men who are the target of positive social interest from women. Our findings demonstrate that social transmission of face preferences influences judgments of men's attractiveness, potentially demonstrating a mechanism for social transmission of mate preferences.     

Face Gender Influences the Looking Preference for Smiling Expressions in 3.5-Month-Old Human Infants

Young infants are typically thought to prefer looking at smiling expressions. Although some accounts suggest that the preference is automatic and universal, we hypothesized that it is not rigid and may be influenced by other face dimensions, most notably the face’s gender. Infants are sensitive to the gender of faces; for example, 3-month-olds raised by female caregivers typically prefer female over male faces. We presented neutral versus smiling pairs of faces from the same female or male individuals to 3.5-month-old infants (n = 25), controlling for low-level cues. Infants looked longer to the smiling face when faces were female but longer to the neutral face when faces were male, i.e., there was an effect of face gender on the looking preference for smiling. The results indicate that a preference for smiling in 3.5-month-olds is limited to female faces, possibly reflective of differential experience with male and female faces.     

Qualitative real-time schlieren and shadowgraph imaging of human exhaled airflows: an aid to aerosol infection control

Using a newly constructed airflow imaging system, airflow patterns were visualized that were associated with common, everyday respiratory activities (e.g. breathing, talking, laughing, whistling). The effectiveness of various interventions (e.g. putting hands and tissues across the mouth and nose) to reduce the potential transmission of airborne infection, whilst coughing and sneezing, were also investigated. From the digital video footage recorded, it was seen that both coughing and sneezing are relatively poorly contained by commonly used configurations of single-handed shielding maneuvers. Only some but not all of the forward momentum of the cough and sneeze puffs are curtailed with various hand techniques, and the remaining momentum is disseminated in a large puff in the immediate vicinity of the cougher, which may still act as a nearby source of infection. The use of a tissue (in this case, 4-ply, opened and ready in the hand) proved to be surprisingly effective, though the effectiveness of this depends on the tissue remaining intact and not ripping apart. Interestingly, the use of a novel 'coughcatcher' device appears to be relatively effective in containing coughs and sneezes. One aspect that became evident during the experimental procedures was that the effectiveness of all of these barrier interventions is very much dependent on the speed with which the user can put them into position to cover the mouth and nose effectively.From these qualitative schlieren and shadowgraph imaging experiments, it is clear that making some effort to contain one's cough or sneeze puffs is worthwhile. Obviously, there will be a large amount of variation between individuals in the exact hand or tissue (the most common methods) configuration used for this and other practical factors may hinder such maneuvers in daily life, for example, when carrying shopping bags or managing young children.     

Coevolution between the large hawk‐cuckoo (Cuculus sparverioides) and its two sympatric Leiothrichidae hosts: evidence for recent expansion and switch in host use?

Obligate brood parasites only account for 1% of birds in the world, but utilize a great variety of avian species as hosts. Host switch theory predicts that parasites should shift from one host to another during the long‐term arms race with hosts whenever such a shift would be facilitated by similarity in ecology and distribution. However, few studies have been conducted to address this puzzle because it is extremely difficult for humans to witness such host shifts during the long‐lasting process of evolution. Here we adopted an alternative way to understand host switch behaviour of brood parasites by comparing egg colour variation, cuckoo egg mimicry and egg recognition capacity between two sympatric hosts, the Chinese babax (Babax lanceolatus) and the white‐browed laughing thrush (Garrulax sannio), which are both parasitized by the large hawk‐cuckoo (Cuculus sparverioides). The babax lays dark blue eggs whilst the laughing thrush lays white to pale blue eggs, and the large hawk‐cuckoo parasitizes them by laying eggs that optimally match laughing thrush eggs according to avian vision. The laughing thrush possesses a greater capacity of egg recognition than the babax because it rejected all non‐mimetic eggs while the babax is an intermediate rejecter. Furthermore, all the nest characteristics measured were similar in these two host species with no statistical significant differences. These results are consistent with the hypothesis that the white‐browed laughing thrush is the original and main host species that has a longer coevolutionary interaction with the large hawk‐cuckoo than the Chinese babax, which is a recent host acquired through a host switch by the hawk‐cuckoo. We discuss the possible outcome of the interaction between the large hawk‐cuckoo and these two host species, and emphasize that host switch behaviour in brood parasites is more likely an adaptation to expand the range of host species rather than a change in host species favoring an increase in reproductive output. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, ●● , ●●–●●.     

Smiles when sharing

One of the proposed functions of human smiling is to advertise cooperative dispositions and thereby increase the likelihood that a social partner would invest resources in a relationship. In particular, smiles involving an emotional component would be honest signals of altruistic dispositions because they are not easy to produce voluntarily. In this study, 60 people were covertly filmed while interacting with a friend in two conditions: control and sharing. Smiles were classified into Duchenne (spontaneous) and non-Duchenne smiles. Participants also completed a series of questionnaires, including the Altruism Scale and a self-report questionnaire of emotional state. Interestingly, Duchenne smiles were displayed at higher rates in the sharing situation as opposed to the control situation, whereas non-Duchenne smiles were unaffected by the type of interaction. Furthermore, Duchenne smiles in the sharing interaction were positively affected by a measure of altruism. Self-reported emotional states did not vary between conditions and were poorly related to smiling. This study shows that the Duchenne smile is relevant to situations that involve the sharing of material resources because it would reliably advertise altruistic intentions. The Duchenne smile could therefore be an important signal in the formation and maintenance of cooperative relationships.     

Face pictures reduce behavioural, autonomic, endocrine and neural indices of stress and fear in sheep

Faces are highly emotive stimuli and we find smiling or familiar faces both attractive and comforting, even as young babies. Do other species with sophisticated face recognition skills, such as sheep, also respond to the emotional significance of familiar faces? We report that when sheep experience social isolation, the sight of familiar sheep face pictures compared with those of goats or inverted triangles significantly reduces behavioural (activity and protest vocalizations), autonomic (heart rate) and endocrine (cortisol and adrenaline) indices of stress. They also increase mRNA expression of activity-dependent genes (c-fos and zif/268) in brain regions specialized for processing faces (temporal and medial frontal cortices and basolateral amygdala) and for emotional control (orbitofrontal and cingulate cortex), and reduce their expression in regions associated with stress responses (hypothalamic paraventricular nucleus) and fear (central and lateral amygdala). Effects on face recognition, emotional control and fear centres are restricted to the right brain hemisphere. Results provide evidence that face pictures may be useful for relieving stress caused by unavoidable social isolation in sheep, and possibly other animal species, including humans. The finding that sheep, like humans, appear to have a right brain hemisphere involvement in the control of negative emotional experiences also suggests that functional lateralization of brain emotion systems may be a general feature in mammals.     

Infants Time Their Smiles to Make Their Moms Smile

One of the earliest forms of interaction between mothers and infants is smiling games. While the temporal dynamics of these games have been extensively studied, they are still not well understood. Why do mothers and infants time their smiles the way they do? To answer this question we applied methods from control theory, an approach frequently used in robotics, to analyze and synthesize goal-oriented behavior. The results of our analysis show that by the time infants reach 4 months of age both mothers and infants time their smiles in a purposeful, goal-oriented manner. In our study, mothers consistently attempted to maximize the time spent in mutual smiling, while infants tried to maximize mother-only smile time. To validate this finding, we ported the smile timing strategy used by infants to a sophisticated child-like robot that automatically perceived and produced smiles while interacting with adults. As predicted, this strategy proved successful at maximizing adult-only smile time. The results indicate that by 4 months of age infants interact with their mothers in a goal-oriented manner, utilizing a sophisticated understanding of timing in social interactions. Our work suggests that control theory is a promising technique for both analyzing complex interactive behavior and providing new insights into the development of social communication.