With friends like you
Michael Sheehan & Michael Nachman
Nature Communications, September 2014
Abstract:
Facial recognition plays a key role in human interactions, and there has been great interest in understanding the evolution of human abilities for individual recognition and tracking social relationships. Individual recognition requires sufficient cognitive abilities and phenotypic diversity within a population for discrimination to be possible. Despite the importance of facial recognition in humans, the evolution of facial identity has received little attention. Here we demonstrate that faces evolved to signal individual identity under negative frequency-dependent selection. Faces show elevated phenotypic variation and lower between-trait correlations compared with other traits. Regions surrounding face-associated single nucleotide polymorphisms show elevated diversity consistent with frequency-dependent selection. Genetic variation maintained by identity signalling tends to be shared across populations and, for some loci, predates the origin of Homo sapiens. Studies of human social evolution tend to emphasize cognitive adaptations, but we show that social evolution has shaped patterns of human phenotypic and genetic diversity as well.
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Delinquency and Peer Acceptance in Adolescence: A Within-Person Test of Moffitt's Hypotheses
Kelly Rulison, Derek Kreager & Wayne Osgood
Developmental Psychology, forthcoming
Abstract:
We tested 2 hypotheses derived from Moffitt's (1993) taxonomic theory of antisocial behavior, both of which are central to her explanation for the rise in delinquency during adolescence. We tested whether persistently delinquent individuals become more accepted by their peers during adolescence and whether individuals who abstain from delinquent behavior become less accepted. Participants were 4,359 adolescents from 14 communities in the PROSPER study, which assessed friendship networks and delinquency from 6th (M = 11.8 years) to 9th (M = 15.3 years) grade. We operationalized peer acceptance as number of nominations received (indegree centrality), attractiveness as a friend (adjusted indegree centrality), and network bridging potential (betweenness centrality) and tested the hypotheses with multilevel modeling. Contrary to Moffitt's hypothesis, persistently delinquent youths did not become more accepted between early and middle adolescence, and although abstainers were less accepted in early adolescence, they became more accepted over time. Results were similar for boys and girls; when differences occurred, they provided no support for Moffitt's hypotheses for boys and were opposite of her hypotheses for girls. Sensitivity analyses in which alternative strategies and additional data were used to identify persistently delinquent adolescents produced similar results. We explore the implications of these results for Moffitt's assertions that social mimicry of persistently antisocial adolescents leads to increases in delinquency and that social isolation leads to abstention.
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Ullrich Wagner et al.
Social Cognitive and Affective Neuroscience, forthcoming
Abstract:
Humans have a strong tendency to affiliate with other people, especially in emotional situations. Here, we suggest that a critical mechanism underlying this tendency is that socially sharing emotional experiences is in itself perceived as hedonically positive and thereby contributes to the regulation of individual emotions. We investigated the effect of social sharing of emotions on subjective feelings and neural activity by having pairs of friends view emotional (negative and positive) and neutral pictures either alone or with the friend. While the two friends remained physically separated throughout the experiment - with one undergoing functional magnetic resonance imaging and the other performing the task in an adjacent room - they were made aware on a trial-by-trial basis whether they were seeing pictures simultaneously with their friend (shared) or alone (unshared). Ratings of subjective feelings were improved significantly when participants viewed emotional pictures together than alone, an effect that was accompanied by activity increase in ventral striatum and medial orbitofrontal cortex, two important components of the reward circuitry. Because these effects occurred without any communication or interaction between the friends, they point to an important proximate explanation for the basic human motivation to affiliate with others, particularly in emotional situations.
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Donald Sacco, Steven Young & Kurt Hugenberg
Personality and Social Psychology Bulletin, forthcoming
Abstract:
The current research provides novel evidence for motivational trade-offs between the two fundamental human goals of pursuing social affiliation and avoiding disease. In Study 1, participants completed a writing prime that manipulated inclusionary status and found that socially excluded participants indicated lower feelings of current disease susceptibility compared with control and socially included participants. In Study 2, participants were included or excluded via Cyberball and then indicated their preferences for symmetrical versus asymmetrical faces. Socially excluded participants displayed lower preferences for symmetrical faces - a cue associated with greater disease resistance. Finally, in Study 3, participants were primed with either disease threat or a general negative affective state and then indicated their current affiliation interest. Activated disease concerns uniquely led participants to display less interest in social affiliation. Taken together, affiliation needs result in disease avoidance down-regulation to aid reaffiliation, whereas disease concerns result in affiliation down-regulation to facilitate pathogen avoidance.
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The Influence of Ethnic Community Knowledge on Indian Inventor Innovativeness
Paul Almeida, Anupama Phene & Sali Li
Organization Science, forthcoming
Abstract:
This paper investigates the knowledge influences of the ethnic community on the quality of innovations of Indian immigrant inventors in the U.S. semiconductor industry. Membership in the Indian ethnic community enables inventors to source knowledge from, and to collaborate with, others in the community. By analyzing patent data, we find that the utility of ethnic knowledge and collaborators depends on the level of inventor embeddedness in the community. Most inventors benefit by sourcing knowledge from, or collaborating with, other Indians and hence enhance innovation quality, but at a diminishing rate. For those who are very heavily embedded in the community, ethnic community knowledge decreases the quality of innovation. Our results provide some support for the idea that simultaneously sourcing ethnic knowledge and using ethnic collaborators also decreases innovativeness. Thus, for Indian inventors, the level of embeddedness in the community is a key factor in influencing the quality of innovation.
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Social-Network Complexity in Humans Is Associated With the Neural Response to Social Information
Sarah Dziura & James Thompson
Psychological Science, forthcoming
Abstract:
Humans have evolved to thrive in large and complex social groups, and it is likely that this increase in group complexity has come with a greater need to decode and respond to complex and uncertain communicatory signals. In this functional MRI study, we examined whether complexity of social networks in humans is related to the functioning of brain regions key to the perception of basic, nonverbal social stimuli. Greater activation to biological than to scrambled motion in the right posterior superior temporal sulcus (pSTS) and right amygdala were positively correlated with the diversity of social-network roles. In the pSTS, in particular, this association was not due to a relationship between network diversity and network size. These findings suggest that increased functioning of brain regions involved in decoding social signals might facilitate the detection and decoding of subtle signals encountered in varied social settings.
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Paolo Riva et al.
Social Neuroscience, forthcoming
Abstract:
Social exclusion, ostracism, and rejection can be emotionally painful because they thwart the need to belong. Building on studies suggesting that the right ventrolateral prefrontal cortex (rVLPFC) is associated with regulation of negative emotions, the present experiment tests the hypothesis that decreasing the cortical excitability of the rVLPFC may increase negative emotional reactions to social exclusion. Specifically, we applied cathodal transcranial direct current stimulation (tDCS) over the rVLPFC and predicted an increment of negative emotional reactions to social exclusion. In Study 1, participants were either socially excluded or included, while cathodal tDCS or sham stimulation was applied over the rVLPFC. Cathodal stimulation of rVLPFC boosted the typical negative emotional reaction caused by social exclusion. No effects emerged from participants in the inclusion condition. To test the specificity of tDCS effects over rVLPFC, in Study 2, participants were socially excluded and received cathodal tDCS or sham stimulation over a control region (i.e., the right posterior parietal cortex). No effects of tDCS stimulation were found. Our results showed that the rVLPFC is specifically involved in emotion regulation and suggest that cathodal stimulation can increase negative emotional responses to social exclusion.
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Autism as a disorder of prediction
Pawan Sinha et al.
Proceedings of the National Academy of Sciences, forthcoming
Abstract:
A rich collection of empirical findings accumulated over the past three decades attests to the diversity of traits that constitute the autism phenotypes. It is unclear whether subsets of these traits share any underlying causality. This lack of a cohesive conceptualization of the disorder has complicated the search for broadly effective therapies, diagnostic markers, and neural/genetic correlates. In this paper, we describe how theoretical considerations and a review of empirical data lead to the hypothesis that some salient aspects of the autism phenotype may be manifestations of an underlying impairment in predictive abilities. With compromised prediction skills, an individual with autism inhabits a seemingly "magical" world wherein events occur unexpectedly and without cause. Immersion in such a capricious environment can prove overwhelming and compromise one's ability to effectively interact with it. If validated, this hypothesis has the potential of providing unifying insights into multiple aspects of autism, with attendant benefits for improving diagnosis and therapy.
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"More Than Words": Social Validation in Close Relationships
Namkje Koudenburg, Ernestine Gordijn & Tom Postmes
Personality and Social Psychology Bulletin, November 2014, Pages 1517-1528
Abstract:
Conversations are susceptible to many disturbances: A speaker's hesitations, distractions, or, when communicating online, technical hiccups that may cause brief delays. Research among previously unacquainted individuals revealed that brief disruptions in conversational flow can have profound social consequences: Silences or delays in mediated communication threaten the need to belong and validate one's ideas. The present research, however, shows that when occurring in close relationships, flow disruptions may be ironically beneficial. We hypothesized that when flow disruptions occur, partners fall back on their relationship beliefs to infer mutual agreement and the existence of a shared reality. When a relationship is perceived as secure, partners may believe that "no words are needed" to understand each other. Flow disruptions can thus paradoxically make shared cognitions accessible and foster feelings of social validation. Data from two experiments, using partners in different types of relationships, supported this hypothesis.
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Try to find me: Social anxiety and peer first impressions
Audrey Aiken et al.
Behavior Therapy, November 2014, Pages 851-862
Abstract:
Following initial interactions, other people are less willing to pursue ongoing contact with socially anxious individuals than with those who are not socially anxious. To better understand this process, we conducted two studies that examined peers' first impressions of target individuals. Unacquainted individuals (N = 104 and 114) participated in round robin, unstructured interactions in groups of 3 to 10 and then rated each partner and themselves on items reflecting the Big-5 personality dimensions. The ratings were analyzed according to Biesanz's social accuracy model of interpersonal perception (SAM; Biesanz, 2010), which distinguishes the positivity from the accuracy of social judgments. Study 1 revealed that perceivers did not view socially anxious targets more negatively or as less likeable than non-socially anxious targets but were less able to recognize their unique personality features. Study 2 replicated those findings and indicated that perceivers' difficulties recognizing socially anxious targets' unique features were not due to negative biases in the socially anxious targets' self-ratings or to general psychological maladjustment. The findings are consistent with cognitive models, which underscore the role of self-concealment in social anxiety disorder.
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Oxytocin increases the likeability of physically formidable men
Frances Chen et al.
Social Cognitive and Affective Neuroscience, forthcoming
Abstract:
Physical size and strength are associated with dominance and threat. The current study tested (i) whether men's evaluations of male strangers would be negatively influenced by cues indicating physical formidability, and (ii) whether these evaluations would be influenced by oxytocin, a neuropeptide that mediates social behavior and reduces social anxiety. In a placebo-controlled, double-blind design, we administered either oxytocin (24 I.U.) or placebo intranasally to 100 healthy males and assessed their responses to an image of either a physically formidable (strong) or physically non-formidable (weak) male peer. Whereas participants receiving placebo expressed dislike and avoidance of the strong male relative to the weak male, oxytocin selectively improved social evaluation of the strong male. These results provide first evidence that oxytocin regulates social evaluation of peers based on body features indicating strength and formidability. We discuss the possibility that oxytocin may promote the expansion of social networks by increasing openness towards potentially threatening individuals.
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Catherine Haslam, Tegan Cruwys & Alexander Haslam
Social Science & Medicine, November 2014, Pages 57-66
Abstract:
Aligned with research in the social capital and general health literature, a large body of evidence shows that older people who are more socially active have better cognitive integrity and are less vulnerable to cognitive decline. The present research addresses the question of whether the type of social engagement (group-based vs. individual) has differential effects on these cognitive health outcomes. Drawing on population data (N=3413) from three waves (i.e., Waves 3, 4 and 5) of the English Longitudinal Study of Aging, we investigated the independent contribution of group and individual engagement in predicting cognitive functioning four years later. Hierarchical linear regression was used entering age, gender, socioeconomic status, ethnicity, and physical health as covariates. The final model, controlling for initial cognitive function and social engagement (both group and individual) showed that only group engagement made a significant, sustained, and unique contribution to subsequent cognitive function. Furthermore, the effects of group engagement were stronger with increasing age. These findings extend previous work on the social determinants of health by pinpointing the types of relationships that are particularly beneficial in protecting cognitive health. The fact that group engagement optimized health outcomes, and that this was especially the case with increasing age, has important implications for directing community resources to keep older adults mentally active and independent for longer.
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Kristin Sommer & Frank Bernieri
Social Psychological and Personality Science, forthcoming
Abstract:
Some studies have revealed evidence for proximity seeking following interpersonal rejection, whereas other studies have found evidence of relational distancing (Williams, 2007). This study examined whether both processes could occur simultaneously within face-to-face interactions. Participants were accepted or rejected by one person and then interacted with a new partner for the purposes of an impression-formation task. Conversations were recorded and transcribed. Dyads containing a previously rejected compared to accepted participant exhibited higher levels of linguistic style matching and reciprocated conversational content, suggestive of proximity seeking. However, rejected targets also rated their new partners as less kind and reported lower levels of rapport/liking for their partners, consistent with relational distancing. Partner evaluations were statistically mediated by targets' expectations of rejection. We suggest that automatic proximity seeking and the appraisal-mediated devaluation of new partners reflect efforts to minimize the potential for and pain of future rejection. Recommendations for future research are discussed.