Presence Of Peers Research Articles

Age differences in the impact of peers on adolescents’ and adults’ neural response to reward

Prior research suggests that increased adolescent risk-taking in the presence of peers may be linked to the influence of peers on the valuation and processing of rewards during decision-making. The current study explores this idea by examining how peer observation impacts the processing of rewards when such processing is isolated from other facets of risky decision-making (e.g. risk-perception and preference, inhibitory processing, etc.). In an fMRI paradigm, a sample of adolescents (ages 14–19) and adults (ages 25–35) completed a modified High/Low Card Guessing Task that included rewarded and un-rewarded trials. Social context was manipulated by having participants complete the task both alone and while being observed by two, same-age, same-sex peers. Results indicated an interaction of age and social context on the activation of reward circuitry during the receipt of reward; when observed by peers adolescents exhibited greater ventral striatal activation than adults, but no age-related differences were evinced when the task was completed alone. These findings suggest that, during adolescence, peers influence recruitment of reward-related regions even when they are engaged outside of the context of risk-taking. Implications for engagement in prosocial, as well as risky, behaviors during adolescence are discussed.

Unity and Diversity

Within the context of the separated youth worship and intergenerational worship debate, this paper considers the voices of young people that have been absent from the discussion. The voice of young people arises from qualitative research conducted in England, Taizé, Singapore, and Nigeria from 2001–2011 by the author. A youth understanding is set out involving the four categories of giving and receiving from God, the presence of peers, fun and learning, and empowerment. The findings of the research contribute a new approach to the worship needs of teenagers.

Proximal and distal social influence on alcohol consumption and marijuana use among middle school adolescents

ObjectivesThis study assesses the independent and combined effects of (1) perceived peer norms, (2) best friend use, and (3) being in the presence of others who use on middle school adolescents’ consumption of marijuana and alcohol, and how the effects of these sources of social influence evolve over time as youth progress through middle school. MethodsThe analytic sample consisted of 11,667 adolescents (50% female; >65% Hispanic) in 6th, 7th or 8th grade from 16 middle schools across three school districts in Southern California. Participants were assessed at 5 time points from 2008 to 2011. ResultsAll sources of social influence were predictive of alcohol and marijuana consumption. As youth grew older, spending time with other adolescents who drink increased adolescents’ likelihood of drinking alcohol, whereas perceived norms became less influential. Furthermore, as adolescents spent more time around other youths who drink, the predictive value of perceived norms on alcohol consumption decreased. Similarly, as youth grew older, the influence of best friend's use and spending time with other adolescents who use marijuana remain stable, whereas perceived norms became less influential. ConclusionFindings suggest that perceived peer norms may be more influential in early adolescence; whereas proximal social determinants (e.g., being in the presence of other peers who consume) become more influential as youth enter middle adolescence. Prevention programs should continue to address misperception of norms with younger adolescents to decrease the chances of initiation, but also utilize strategies such as refusal skills and alternate coping mechanisms for older adolescents.

Social Media Effects on Young Women’s Body Image Concerns: Theoretical Perspectives and an Agenda for Research

Although there is a voluminous literature on mass media effects on body image concerns of young adult women in the U.S., there has been relatively little theoretically-driven research on processes and effects of social media on young women’s body image and self-perceptions. Yet given the heavy online presence of young adults, particularly women, and their reliance on social media, it is important to appreciate ways that social media can influence perceptions of body image and body image disturbance. Drawing on communication and social psychological theories, the present article articulates a series of ideas and a framework to guide research on social media effects on body image concerns of young adult women. The interactive format and content features of social media, such as the strong peer presence and exchange of a multitude of visual images, suggest that social media, working via negative social comparisons, transportation, and peer normative processes, can significantly influence body image concerns. A model is proposed that emphasizes the impact of predisposing individual vulnerability characteristics, social media uses, and mediating psychological processes on body dissatisfaction and eating disorders. Research-based ideas about social media effects on male body image, intersections with ethnicity, and ameliorative strategies are also discussed.

Neural Responses to Exclusion Predict Susceptibility to Social Influence

PurposeSocial influence is prominent across the lifespan, but sensitivity to influence is especially high during adolescence and is often associated with increased risk taking. Such risk taking can have dire consequences. For example, in American adolescents, traffic-related crashes are leading causes of nonfatal injury and death. Neural measures may be especially useful in understanding the basic mechanisms of adolescents' vulnerability to peer influence. MethodsWe examined neural responses to social exclusion as potential predictors of risk taking in the presence of peers in recently licensed adolescent drivers. Risk taking was assessed in a driving simulator session occurring approximately 1 week after the neuroimaging session. ResultsIncreased activity in neural systems associated with the distress of social exclusion and mentalizing during an exclusion episode predicted increased risk taking in the presence of a peer (controlling for solo risk behavior) during a driving simulator session outside the neuroimaging laboratory 1 week later. These neural measures predicted risky driving behavior above and beyond self-reports of susceptibility to peer pressure and distress during exclusion. ConclusionsThese results address the neural bases of social influence and risk taking; contribute to our understanding of social and emotional function in the adolescent brain; and link neural activity in specific, hypothesized, regions to risk-relevant outcomes beyond the neuroimaging laboratory. Results of this investigation are discussed in terms of the mechanisms underlying risk taking in adolescents and the public health implications for adolescent driving.

Social context: Key to understanding culture's effects on creativity

SummaryThis paper proposes that the social context moderates the effect of culture on creativity by drawing on the constructivist dynamic approach. We assess creativity by the level of fluency, originality, and elaboration on the usefulness and appropriateness of ideas in three contexts: working under a supervisor, in a group, and alone. We hypothesized that in high power distance cultures, working under a supervisor inhibits creativity, whereas in individualistic cultures, the presence of peers attenuates creativity. Results from two parallel experiments, one in the United States (N = 79) and the other in China (N = 83), partially support the hypotheses. The Chinese originality level was significantly lower when working under a supervisor than when working alone. American subjects generated fewer ideas and elaborated less when working in the presence of peers and elaborated less in the presence of peers than when under a supervisor. We conclude that the social context moderates the culture–creativity relationship by making consensual cultural values more accessible in a social context than when working alone. Copyright © 2014 John Wiley & Sons, Ltd.

Social learning reverses conditioned aversion to nicotine via oxytocin receptor in the infralimbic cortex in rats (839.4)

The initial aversive response to cigarettes in most smokers is thought to be ameliorated by the presence of peers who also smoke. We previously reported that social learning (i.e. detecting an odor cue associated with nicotine from peer rats) reversed the development of conditioned taste aversion (CTA) between self‐administered nicotine and a contingent olfactogustatory cue in adolescent rats (PMID:21796102). Herein, we focused on the role of oxytocin in infralimbic cortex (IL) as a mechanism for the effect of social learning. Bilateral lesions of IL before (F1,13=18.1, p=0.001) but not after (F1,16=0.481, p>0.05) self‐administration reduced the effect of social learning on tests of CTA. We also found that carbon disulfide contained in rats’ breath was the signal mediating social learning and its effect also required intact IL. We then infused a specific oxytocin receptor antagonist, desGly‐NH2‐d(CH2)5[D‐Tyr]OVT, (0.028 ~ 2.8 μg/ml, a gift from Dr. Mannings) bilaterally into the IL, which dose‐dependently reduced the effect of carbon disulfide on nicotine CTA (F4,30=3.9, p=0.01). The highest dose of the antagonist had no effect on i.v. saline control rats. These results suggested that the release of oxytocin in the IL is a critical signal that reversed the conditioned aversion between nicotine and its olfactogustatory cue, which in turn enabled voluntary nicotine intake in adolescent rats.Key words: nicotine; aversion; social learning; infralimbic cortex; oxytocin

With a Little Help From My Friends: Bystander Context and Children's Attitude Toward Peer Helping

This experimental vignette study examined children's perceptions and evaluations of helping a peer, in the context of friendships and in the presence of by-standing peers. A total of 1246 children (8 to 12 years) reported their attitude toward helping when either friends of the helper, friends of the recipient of help, or no bystanders were present. In agreement with the competitive altruism model, children most strongly endorsed helping when friends of the helper were present compared to the other two situations. This indicates that children take reputation concerns into account when evaluating helping situations. However, in contrast to lower prosocial children, the evaluations of higher prosocial children were not influenced by the presence of by-standing peers. These children seemed to base their evaluation on increasing the recipient's welfare and less on reputation concerns of the helper.

Weaving Straw into Gold: Managing Organizational Tensions Between Standardization and Flexibility in Microfinance

This article explores how organizations balance the pressures to pursue efficiency through standardization with the need to remain responsive to local needs. The study combines rich ethnography with detailed loan data to show that both standardization and flexibility through relational ties provide substantial organizational benefits but also carry significant costs; thus, no strategy is inherently superior, and their coexistence generates the best results. Such coexistence, however, creates contradictions that must be managed. Here, I use microfinance as a strategic setting and gain analytic leverage from the random assignment across branches of loan officers who exhibit significant heterogeneity in rule enforcement styles: some enforce rules strictly, whereas others frequently bend them to respond to client needs. I find that loan officers with relational styles exercise discretion productively to enhance organizational performance. Yet their effectiveness is contingent on the presence of rule-enforcing peers, as evidenced by the significant underperformance of branches with a high concentration of officers of either type. In contrast, branches that contain discretionary diversity, or a balance between enforcement styles, perform best. This is not due to diversity per se, but because loan officers process decisions in local credit committees. Committees that contain discretionary diversity generate a productive tension that induces participants to justify decisions along broader organizational goals, thus maintaining a productive balance between standardization and flexibility. Implications for organizational theory and practice are discussed.

Peers increase adolescent risk taking even when the probabilities of negative outcomes are known.

The majority of adolescent risk taking occurs in the presence of peers, and recent research suggests that the presence of peers may alter how the potential rewards and costs of a decision are valuated or perceived. The current study further explores this notion by investigating how peer observation affects adolescent risk taking when the information necessary to make an informed decision is explicitly provided. We used a novel probabilistic gambling task in which participants decided whether to play or pass on a series of offers for which the reward and loss outcome probabilities were made explicit. Adolescent participants completed the task either alone or under the belief that they were being observed by an unknown peer in a neighboring room. Participants who believed a peer was observing them chose to gamble more often than participants who completed the task alone, and this effect was most evident for decisions with a greater probability of loss. These results suggest that the presence of peers can increase risk taking among adolescents even when specific information regarding the likelihood of positive and negative outcomes is provided. The findings expand our understanding of how peers influence adolescent decision making and have important implications regarding the value of educational programs aimed at reducing risky behaviors during adolescence.

Adolescents’ risky decision-making activates neural networks related to social cognition and cognitive control processes

This study examines by means of functional magnetic resonance imaging the neural mechanisms underlying adolescents’ risk decision-making in social contexts. We hypothesize that the social context could engage brain regions associated with social cognition processes and developmental changes are also expected. Sixty participants (adolescents: 17–18, and young adults: 21–22 years old) read narratives describing typical situations of decision-making in the presence of peers. They were asked to make choices in risky situations (e.g., taking or refusing a drug) or ambiguous situations (e.g., eating a hamburger or a hotdog). Risky as compared to ambiguous scenarios activated bilateral temporoparietal junction (TPJ), bilateral middle temporal gyrus (MTG), right medial prefrontal cortex, and the precuneus bilaterally; i.e., brain regions related to social cognition processes, such as self-reflection and theory of mind (ToM). In addition, brain structures related to cognitive control were active [right anterior cingulate cortex (ACC), bilateral dorsolateral prefrontal cortex (DLPFC), bilateral orbitofrontal cortex], whereas no significant clusters were obtained in the reward system (ventral striatum). Choosing the dangerous option involved a further activation of control areas (ACC) and emotional and social cognition areas (temporal pole). Adolescents employed more neural resources than young adults in the right DLPFC and the right TPJ in risk situations. When choosing the dangerous option, young adults showed a further engagement in ToM related regions (bilateral MTG) and in motor control regions related to the planning of actions (pre-supplementary motor area). Finally, the right insula and the right superior temporal gyrus were more activated in women than in men, suggesting more emotional involvement and more intensive modeling of the others’ perspective in the risky conditions. These findings call for more comprehensive developmental accounts of decision-making in social contexts that incorporate the role of emotional and social cognition processes.

Collective behavior and predation success in a predator-prey model inspired by hunting bats

We establish an agent-based model to study the impact of prey behavior on the hunting success of predators. The predators and prey are modeled as self-propelled particles moving in a three-dimensional domain and subject to specific sensing abilities and behavioral rules inspired by bat hunting. The predators randomly search for prey. The prey either align velocity directions with peers, defined as "interacting" prey, or swarm "independently" of peer presence; both types of prey are subject to additive noise. In a simulation study, we find that interacting prey using low noise have the maximum predation avoidance because they form localized large groups, while they suffer high predation as noise increases due to the formation of broadly dispersed small groups. Independent prey, which are likely to be uniformly distributed in the domain, have higher predation risk under a low noise regime as they traverse larger spatial extents. These effects are enhanced in large prey populations, which exhibit more ordered collective behavior or more uniform spatial distribution as they are interacting or independent, respectively.

The influence of friends and peers on children’s food intake. An experimental study

School-aged children spend a substantial amount of time interacting with other children. Recent work has suggested that peers and friends influence children’s eating attitudes and behaviours, but it is unclear whether there are any differences between the effect that friends versus peers may have on children’s eating. The research presented considers the effect of groups of friends and groups of peers on preadolescent children’s food intake. Following their school lunch, children aged 8–9 years were offered free access to two energy dense foods (chocolate cookies and crisps) and two nutrient dense foods (carrot sticks and apple pieces) whilst completing a game task. On one occasion children played and ate with a group of friends, on the other with a group of familiar peers. Gender differences in consumption were observed. For boys, there were significant differences in the consumption of both of the nutrient dense foods, with boys consuming more carrots and apples when with their friends, compared to with their peers. For girls, there was a significant difference in consumption for carrots only, such that girls consumed more carrots when in the presence of friends, compared to peers. In terms of overall consumption levels, boys consumed significantly more when with their friends, compared to with their peers. The same was not found for girls. The results provide some evidence that social context (being in the presence of friends or peers) and gender may have a differential impact on consumption in preadolescent children.

On the performance and fairness of BitTorrent-like data swarming systems with NAT devices

There is no doubt that BitTorrent nowadays is one of the most popular peer-to-peer (P2P) applications on the Internet. On the other hand, Network Address Translation (NAT) has become pervasive in almost all networking scenarios. Despite the effort of NAT traversal, it is still very likely that applications, especially P2P ones, cannot receive incoming connection requests properly if they are behind NAT. In this paper, we build analytical models to characterize BitTorrent-like P2P systems with the presence of homogeneous and heterogeneous NAT peers, from which we observe and mathematically reason the poor download performance of NAT peers. Motivated by this observation, we further investigate the fairness metrics of the system, which reveal the fundamental problem of the BitTorrent unchoke mechanism: it is unaware of, and unfair to NAT peers. We thus propose a tunable optimistic unchoke strategy, in order to improve the overall system performance and fairness metrics considerably. The simulation results have validated our analytical models, and also the efficacy of our tunable optimistic unchoke strategy.

Adolescent mice, unlike adults, consume more alcohol in the presence of peers than alone

One hallmark of adolescent risk-taking is that it typically occurs when adolescents are with peers. It has been hypothesized that the presence of peers primes a reward-sensitive motivational state that overwhelms adolescents' immature capacity for inhibitory control. We examined this hypothesis using a rodent model. A sample of mice were raised in same-sex triads and were tested for alcohol consumption either as juveniles or as adults, with half in each age group tested alone and half tested with their cagemates. The presence of 'peers' increased alcohol consumption among adolescent mice, but not adults. The peer effect on human adolescent reward-seeking may reflect a hard-wired, evolutionarily conserved process through which the presence of agemates increases individuals' sensitivity to potential rewards in their immediate environment.

Effects of anonymous peer observation on adolescents' preference for immediate rewards

Research suggests that the presence of peers influences adolescent risk-taking by increasing the perceived reward value of risky decisions. While prior work has involved observation of participants by their friends, the current study examined whether observation by an anonymous peer could elicit similarly increased reward sensitivity. Late adolescent participants completed a delay discounting task either alone or under the belief that performance was being observed from a neighboring room by an unknown viewer of the same gender and age. Even in this limited social context, participants demonstrated a significantly increased preference for smaller, immediate rewards when they believed that they were being watched. This outcome challenges several intuitive accounts of the peer effect on adolescent risk-taking, and indicates that the peer influence on reward sensitivity during late adolescence is not dependent on familiarity with the observer. The findings have both theoretical and practical implications for our understanding of social influences on adolescents' risky behavior.

Antecedents and consequences of pediatric dog-bite injuries and their developmental trends: 101 cases in rural China

ObjectiveStudy the contextual antecedents and consequences of pediatric dog bites in rural China. MethodsA total of 101 caregivers from rural Anhui Province, China, whose children had suffered dog-bite injuries in the past year, participated in a structured interview about the circumstances, antecedents and consequences of their child's injury. ResultsContextual circumstances identified frequently included outside-home environment and presence of peers but not adult supervisors. Frequent antecedents were dogs’ initiation of the encounter, children walking to/from school, and dogs unleashed. Consequences to children identified frequently were rabies vaccines, restricted activity, and fear of dogs. Developmental trends emerged, with bite circumstances differing by children's ages. ConclusionsThese results offer data on common antecedents and consequences of pediatric dog bites in rural China, a necessary prerequisite for development of empirically supported prevention programs in a vulnerable population.

Analogue Study of Peer Influence on Risk-Taking Behavior in Older Adolescents

This experimental study aimed to examine whether adolescents act in a riskier manner in the presence of peers and whether peer presence alone influences risk behavior or if a direct influence process is necessary. Utilizing a behavioral task assessing risk-taking, 183 older adolescents (18–20 year olds) came to the laboratory alone once and then were randomized to one of three conditions as follows: alone, peers present, and peers encouraging. An interaction was found such that at baseline, there were no significant differences between the three conditions, but at the experimental session, there was a significant increase in risk task scores particularly for the encouraging condition. These findings challenge proposed models of the interaction between peer influence and risk taking by providing evidence that adolescents take more risks when being encouraged by peers, but that the presence of peers on its own does not lead to more risks than when completing the task alone.

Identification of Malicious Nodes in Peer-to-Peer Streaming: A Belief Propagation-Based Technique

Peer-to-peer streaming has witnessed a great success thanks to the possibility of aggregating resources from all participants. Nevertheless, performance of the entire system may be highly degraded due to the presence of malicious peers that share bogus data on purpose. In this paper, we propose to use a statistical inference technique, namely, belief propagation (BP), to estimate the probability of peers being malicious. The detection algorithm is run by a set of trusted monitor nodes that receives notification messages (checks) from peers whenever they obtain a chunk of data; these checks contain the list of the chunk uploaders and a flag to mark the chunk as polluted or clean. Peers are able to detect if the received chunk is polluted or not but, since multiparty download is employed, they are not capable to identify the source(s) of bogus blocks. This problem definition allows us to define a factor graph of peers and checks on which an incremental version of the belief propagation algorithm is run by the monitor nodes to infer the probability of each peer being a malicious one. We evaluate the accuracy, robustness, and complexity of our technique by running a real peer-to-peer application on PlanetLab. We show that the proposed approach is very accurate and robust against malicious nodes misbehaving (different pollution intensity, presence of fake checks, churning, and total uncooperation from malicious nodes), increasing number and colluding behavior of malicious nodes.

The role of perceptions of friendships and peers in learning skills in physical education

Background: Most research on how children learn when using the Teaching Games for Understanding (TGfU) approach has focused on cognitive dimensions in teaching games models. A social constructivist perspective suggests, however, that learning also takes place during social interactions. Since the process of learning game skills tends to have a relational dimension, researchers need to understand children's affective responses and how they situate their skill learning in games in relationship to their classmates.Purpose: To explore children's perceptions of collaboration, group formations, and friendships while learning a modified baseball game situated in social constructivist learning. Specifically, we focused on how children perceived the role that the social context, especially friends and classmates, plays in learning skills and strategies.Participants and setting: The children (N = 25), aged 12–13, were in their first year of secondary school and were taught in a TGfU baseball unit. They participated in eight small focus groups to talk about their experiences in a modified baseball game.Data analysis: The constant comparative method was used to collect data in which drawings were used as cues for focus group discussions about interactions with peers during their learning of skills.Findings: Three themes emerged from the analysis: peers as necessary collaborators, friends as supporters and distractors, and peers as perceived critics. The results indicated that the presence of peers shaped the experiences of these children in contradictory ways. Findings were situated within social constructivism and compared with other research focusing on game-centered approaches and the role of the affective domain in learning.