Reinforcement Learning Signal Predicts Social Conformity

Social sharing of emotion during the collective crisis of COVID-19

We collected data from two sources - social media and online questionnaires - to investigate the emotional consequences of social sharing during the COVID-19 pandemic. Study 1 tracked and analysed sentiment of tweets posted over the course of a month in the crisis period and found that users who tweeted more frequently about COVID-19 expressed decreasing negative sentiment and increasing positive sentiment over time. Granger causality tests confirmed that this association was better interpreted in the forward direction (sharing levels predicting sentiment) than in the reverse direction (sentiment predicting sharing levels). Study 2 focused on immediate emotional consequences of sharing COVID-19-related events and found that participants reported improved overall affect about an event after sharing it, especially when that event was a personal experience rather than a news story. Reported positive feelings about both kinds of events were also significantly higher after sharing. Taken together, both studies suggested that social sharing is linked with emotional relief and may therefore help people to deal with their negative experiences during a persistent collective crisis.

Considering information-sharing motives to reduce misinformation

Misinformation has risen in recent years, negatively affecting domains ranging from politics to health. To curb the spread of misinformation it is useful to consider why, how, and when people decide to share information. Here we suggest that information-sharing decisions are value-based choices, in which sharers strive to maximize rewards and minimize losses to themselves and/or others. These outcomes can be tangible, in the form of monetary rewards or losses, or intangible, in the form of social feedback. On social media platforms these rewards and losses are not clearly tied to the accuracy of information shared. Thus, sharers have little incentive to avoid disseminating misinformation. Based on this framework, we propose ways to nudge sharers to prioritize accuracy during information-sharing.

Neural Tracking of Perceived Parent, but Not Peer, Norms Is Associated with Longitudinal Changes in Adolescent Attitudes about Externalizing Behaviors

Adolescents' perceptions of parent and peer norms about externalizing behaviors influence the extent to which they adopt similar attitudes, yet little is known about how the trajectories of perceived parent and peer norms are related to trajectories of personal attitudes across adolescence. Neural development of midline regions implicated in self-other processing may underlie developmental changes in parent and peer influence. Here, we examined whether neural processing of perceived parent and peer norms in midline regions during self-evaluations would be associated with trajectories of personal attitudes about externalizing behaviors. Trajectories of adolescents' perceived parent and peer norms were examined longitudinally with functional neuroimaging (n = 165; ages 11-16 years across three waves; 86 girls, 79 boys; 29.7% White, 21.8% Black, 35.8% Latinx, 12.7% other/multiracial). Behavioral results showed perceived parent norms were less permissive than adolescents' own attitudes about externalizing behaviors, whereas perceived peer norms were more permissive than adolescents' own attitudes, effects that increased from early to middle adolescence. Although younger adolescents reported less permissive attitudes when they spontaneously tracked perceived parent norms in the ventromedial and medial pFCs during self-evaluations, this effect weakened as they aged. No brain-behavior effects were found when tracking perceived peer norms. These findings elucidate how perceived parent and peer norms change in parallel with personal attitudes about externalizing behaviors from early to middle adolescence and underscore the importance of spontaneous neural tracking of perceived parent norms during self-evaluations for buffering permissive personal attitudes, particularly in early adolescence.

Social cues influence perception of others' pain

BACKGROUND

Accurately perceiving other people's pain is important in both daily life and healthcare settings. However, judging other's pain is inherently difficult and can be biased by various social and cultural factors. Here, we examined whether perception of others' pain and pain management recommendations are socially influenced by seeing the opinions of other raters.

METHODS

In Experiment 1 (N = 50), participants rated pictures depicting injured hands or feet of pre-selected high, medium and low intensities. Each picture was preceded by cues indicating ratings of 10 previous participants. Cues were randomized to indicate low (SocialLOW) or high (SocialHIGH) pain judgements and were not predictive of actual normative pain intensity. In Experiment 2 (N = 209), participants viewed facial video clips of patients with chronic shoulder pain making painful movements. They estimated patients' pain intensity and provided pain management recommendations.

RESULTS

Experiment 1 revealed that perceivers' pain estimates were significantly and substantially higher for stimuli following SocialHIGH than SocialLOW cues (Cohen's d = 1.26, p < 0.001) and paralleled by increased skin conductance responses. Experiment 2 replicated the effect of social cues on pain judgements (d = 0.58, p < 0.001). However, social cues did not influence post-study pain management recommendations, potentially due to memory limitations.

CONCLUSIONS

Together, these studies reveal that judgements of others' pain are robustly modulated by information about others' opinions. Future research could test the prevalence and strength of such effects in clinical settings.

SIGNIFICANCE

The present study shows that even arbitrary opinions of other raters influence the perception of others' pain. This finding adds new insight into the growing evidence of social and cultural biases in pain estimation.

Imagination vs. routines: festive time, weekly time, and the predictive brain

This paper examines the relationship between societal structures shaped by traditions, norms, laws, and customs, and creative expressions in arts and media through the lens of the predictive coding framework in cognitive science. The article proposes that both dimensions of culture can be viewed as adaptations designed to enhance and train the brain's predictive abilities in the social domain. Traditions, norms, laws, and customs foster shared predictions and expectations among individuals, thereby reducing uncertainty in social environments. On the other hand, arts and media expose us to simulated experiences that explore alternative social realities, allowing the predictive machinery of the brain to hone its skills through exposure to a wider array of potentially relevant social circumstances and scenarios. We first review key principles of predictive coding and active inference, and then explore the rationale of cultural traditions and artistic culture in this perspective. Finally, we draw parallels between institutionalized normative habits that stabilize social worlds and creative and imaginative acts that temporarily subvert established conventions to inject variability.

Higher Numbers of Family Meals and Social Eating Behavior Are Associated with Greater Self-Esteem among Adolescents: The EHDLA

BACKGROUND

the aim of this study was to assess the associations of family meals and social eating behavior with self-esteem levels among Spanish adolescents.

METHODS

This was a secondary cross-sectional study including 706 participants (aged 12 to 17 years; 56.1% girls) from the Eating Habits and Daily Life Activities (EHDLA) study. The evaluation of the frequency of family meals involved participants providing information in physical education classes on how frequently they, along with other members of their household, had shared meals in the previous week. Social eating behavior was assessed by three different statements: "I usually have dinner with others", "Having at least one meal a day with others (family or friends) is important to me", and "I enjoy sitting down with family or friends for a meal". To assess overall self-esteem, the Rosenberg Self-Esteem Scale was used.

RESULTS

In the adjusted models, a positive association was observed between the frequency of family meals and the self-esteem score (unstandardized beta coefficient [B] = 0.06, 95% confidence interval [CI] 0.003 to 0.12, p-adjusted = 0.040). Furthermore, the same positive association was also identified between social eating behavior and the self-esteem score (B = 0.23; 95% CI 0.07 to 0.40, p-adjusted = 0.005).

CONCLUSIONS

Although self-esteem is complex and can be influenced by numerous factors, both family meals and social eating behavior may exert a relevant role in adolescents. Encouraging consistent participation in family meals and promoting positive eating practices could be valuable approaches in public health actions targeting the enhancement of self-esteem levels in adolescents.

Neural asymmetry in aligning with generous versus selfish descriptive norms in a charitable donation task

Social alignment is supported by the brain's reward system (ventral striatum), presumably because attaining synchrony generates feelings of connectedness. However, this may hold only for aligning with generous others, while aligning with selfishness might threaten social connectedness. We investigated this postulated asymmetry in an incentivized fMRI charitable donation task. Participants decided how much of their endowment to donate to real charities, and how much to keep for themselves. Compared to a baseline condition, donations significantly increased or decreased in function of the presence of descriptive norms. The fMRI data reveal that processing selfish norms (more than generous ones) recruited the amygdala and anterior insula. Aligning with selfish norms correlated on average with reduced activity in the lateral prefrontal cortex (LPFC) and, at the individual level, with decreasing activity in the ventral striatum (VS). Conversely, as participants aligned more with generous norms, they showed increasing activity in the LPFC and, on average, increased activity in the VS. This increase occurred beyond the increased VS activity which was also observed in the baseline condition. Taken together, this suggests that aligning with generosity, while effortful, provides a "warm glow of herding" associated with collective giving, but that aligning with selfishness does not.

Effort expenditure modulates feedback evaluations involving self-other agreement: evidence from brain potentials and neural oscillations

The influence of effort expenditure on the subjective value in feedback involving material reward has been the focus of previous research. However, little is known about the impact of effort expenditure on subjective value evaluations when feedback involves reward that is produced in the context of social interaction (e.g. self-other agreement). Moreover, how effort expenditure influences confidence (second-order subjective value) in feedback evaluations remains unclear. Using electroencephalography, this study aimed to address these questions. Event-related potentials showed that, after exerting high effort, participants exhibited increased reward positivity difference in response to self-other (dis)agreement feedback. After exerting low effort, participants reported high confidence, and the self-other disagreement feedback evoked a larger P3a. Time-frequency analysis showed that the high-effort task evoked increased frontal midline theta power. In the low (vs. high)-effort task, the frontal midline delta power for self-other disagreement feedback was enhanced. These findings suggest that, at the early feedback evaluation stage, after exerting high effort, individuals exhibit an increased sensitivity of subjective value evaluation in response to self-other agreement feedback. At the later feedback evaluation stage, after completing the low-effort task, the self-other disagreement feedback violates the individuals'high confidence and leads to a metacognitive mismatch.

Neurophysiological correlates of interpersonal discrepancy and social adjustment in an interactive decision-making task in dyads

Introduction

The pursuit of convergence and the social behavioral adjustment of conformity are fundamental cooperative behaviors that help people adjust their mental frameworks to reach a common goal. However, while social psychology has extensively studied conformity by its influence context, there is still plenty to investigate about the neural cognitive mechanisms involved in this behavior.

Methods

We proposed a paradigm with two phases, a pre-activation phase to enhance cooperative tendencies and, later, a social decision-making phase in which dyads had to make a perceptual estimation in three consecutive trials and could converge in their decisions without an explicit request or reward to do so. In Study 1, 80 participants were divided in two conditions. In one condition participants did the pre-activation phase alone, while in the other condition the two participants did it with their partners and could interact freely. In Study 2, we registered the electroencephalographical (EEG) activity of 36 participants in the social decision-making phase.

Results

Study 1 showed behavioral evidence of higher spontaneous convergence in participants who interacted in the pre-activation phase. Event related Potentials (ERP) recorded in Study 2 revealed signal differences in response divergence in different time intervals. Time-frequency analysis showed theta, alpha, and beta evidence related to cognitive control, attention, and reward processing associated with social convergence.

Discussion

Current results support the spontaneous convergence of behavior in dyads, with increased behavioral adjustment in those participants who have previously cooperated. In addition, neurophysiological components were associated with discrepancy levels between participants, and supported the validity of the experimental paradigm to study spontaneous social behavioral adaptation in experimental settings.

Social influence in adolescence: Behavioral and neural responses to peer and expert opinion

Social influence plays a crucial role during the teen years, with adolescents supposedly exhibiting heightened sensitivity to their peers. In this study, we examine how social influence from different sources, particularly those with varying normative and informational significance, affect adolescents' opinion change. Furthermore, we investigated the underlying neural dynamics to determine whether these two behaviorally similar influences share their neural mechanisms. Twenty-three participants (14-17 years old) gave their opinions about facial stimuli and received feedback from either a peer group or an expert group, while brain responses were recorded using concurrent magnetoencephalography. In a second rating session, we found that participants' opinions changed in line with conflicting feedback, but only when the feedback was lower than their initial evaluation. On the neural level, conflict with peers evoked stronger neural responses than conflict with experts in the 230-400 ms time window and the right frontotemporal magnetometer channels. Nevertheless, there was no greater conformity toward peers. Moreover, conflict compared to no conflict decreased neural oscillations in the beta frequency range (20-26 Hz) at the right frontal and parietal channels. Taken together, our findings do not support the general assumption that adolescent behavior is excessively vulnerable to peer norms, although we found heightened neural sensitivity to peer feedback.

Adaptive adjustment after conflict with group opinion: evidence from neural electrophysiology

Individuals inherently seek social consensus when making decisions or judgments. Previous studies have consistently indicated that dissenting group opinions are perceived as social conflict that demands attitude adjustment. However, the neurocognitive processes of attitude adjustment are unclear. In this electrophysiological study, participants were recruited to perform a face attractiveness judgment task. After forming their own judgment of a face, participants were informed of a purported group judgment (either consistent or inconsistent with their judgment), and then, critically, the same face was presented again. The neural responses to the second presented faces were measured. The second presented faces evoked a larger late positive potential after conflict with group opinions than those that did not conflict, suggesting that more motivated attention was allocated to stimulus. Moreover, faces elicited greater midfrontal theta (4-7 Hz) power after conflict with group opinions than after consistency with group opinions, suggesting that cognitive control was initiated to support attitude adjustment. Furthermore, the mixed-effects model revealed that single-trial theta power predicted behavioral change in the Conflict condition, but not in the No-Conflict condition. These findings provide novel insights into the neurocognitive processes underlying attitude adjustment, which is crucial to behavioral change during conformity.

A frontopolar-temporal circuit determines the impact of social information in macaque decision making

When choosing, primates are guided not only by personal experience of objects but also by social information such as others' attitudes toward the objects. Crucially, both sources of information-personal and socially derived-vary in reliability. To choose optimally, one must sometimes override choice guidance by personal experience and follow social cues instead, and sometimes one must do the opposite. The dorsomedial frontopolar cortex (dmFPC) tracks reliability of social information and determines whether it will be attended to guide behavior. To do this, dmFPC activity enters specific patterns of interaction with a region in the mid-superior temporal sulcus (mSTS). Reversible disruption of dmFPC activity with transcranial ultrasound stimulation (TUS) led macaques to fail to be guided by social information when it was reliable but to be more likely to use it when it was unreliable. By contrast, mSTS disruption uniformly downregulated the impact of social information on behavior.

Rethinking Norm Psychology

Norms permeate human life. Most of people's activities can be characterized by rules about what is appropriate, allowed, required, or forbidden-rules that are crucial in making people hyper-cooperative animals. In this article, I examine the current cognitive-evolutionary account of "norm psychology" and propose an alternative that is better supported by evidence and better placed to promote interdisciplinary dialogue. The incumbent theory focuses on rules and claims that humans genetically inherit cognitive and motivational mechanisms specialized for processing these rules. The cultural-evolutionary alternative defines normativity in relation to behavior-compliance, enforcement, and commentary-and suggests that it depends on implicit and explicit processes. The implicit processes are genetically inherited and domain-general; rather than being specialized for normativity, they do many jobs in many species. The explicit processes are culturally inherited and domain-specific; they are constructed from mentalizing and reasoning by social interaction in childhood. The cultural-evolutionary, or "cognitive gadget," perspective suggests that people alive today-parents, educators, elders, politicians, lawyers-have more responsibility for sustaining normativity than the nativist view implies. People's actions not only shape and transmit the rules, but they also create in each new generation mental processes that can grasp the rules and put them into action.

Social norms shape visual appearance: Taking a closer look at the link between social norm learning and perceptual decision-making

One of the most fundamental questions in social psychology is whether norms can change individuals' minds by shaping the visual appearance of stimuli. This question was first raised by Muzafer Sherif (1935). Drawing on the extended social reinforcement account (Germar and Mojzisch, 2019), we aimed to provide a rigorous test of the hypothesis that norm learning leads to a persistent perceptual bias and, hence, to a change in the visual appearance of stimuli. From a methodological perspective, we used both a diffusion model approach and the method of adjustment, a well-established technique from psychophysics and vision research. The results of Experiments 1-3 show that norm effects on perceptual decision-making are robustly replicable, and are due to genuine social influence, that is, they cannot be explained by non-social priming, contingency learning effects (Experiments 1 and 2) or anchoring effects (Experiment 3). Most importantly, by using a psychophysical approach, Experiment 4 shows, for the first time, that social norm learning alters individuals' point of subjective equality and, hence, the visual appearance of stimuli.

The detection of self-group conflicts in exercise behaviors differs with social network centrality: ERP evidence

BACKGROUND

The influence of social norms on exercise behaviors has been explored in studies over the years. However, little is known about whether an individual's role (central or peripheral) in his or her social network, which is associated with social skills, could shift his or her susceptibility to normative effects on exercise behaviors. To that end, event-related potentials (ERPs) were recorded to examine the underlying cognitive mechanism of the effects of network centrality on normative social influence.

METHODS

We manipulated network centrality by assigning participants to exercise support groups, with group members who were their nominated friends (high centrality) or nonnominated classmates (low centrality). Participants were asked to evaluate their willingness to engage in various exercises, after viewing discrepant group ratings (peer influence) or not viewing (no-influence).

RESULTS

Peer influence evoked a larger negative-going feedback-related negativity (FRN) wave, which was linked to automatic social conflict detection, and a larger positive-going P3 wave, which was linked to subsequent conformity behavioral changes. However, effects on the FRN, not the P3, were observed only in the high-centrality group.

CONCLUSION

Our results highlight the important roles of network centrality in encoding self-group exercise attitude discrepancy rather than in decision-making regarding exercise attitude adjustments. Interventions aimed at promoting exercise behaviors should be considered in a broader social environmental framework.

Revealing the Selectivity of Neuroanatomical Alteration in Autism Spectrum Disorder via Reverse Inference

BACKGROUND

Although neuroimaging research has identified atypical neuroanatomical substrates in individuals with autism spectrum disorder (ASD), it is at present unclear whether and to what extent disorder-selective gray matter alterations occur in this spectrum of conditions. In fact, a growing body of evidence shows a substantial overlap between the pathomorphological changes across different brain diseases, which may complicate identification of reliable neural markers and differentiation of the anatomical substrates of distinct psychopathologies.

METHODS

Using a novel data-driven and Bayesian methodology with published voxel-based morphometry data (849 peer-reviewed experiments and 22,304 clinical subjects), this study performs the first reverse inference investigation to explore the selective structural brain alteration profile of ASD.

RESULTS

We found that specific brain areas exhibit a >90% probability of gray matter alteration selectivity for ASD: the bilateral precuneus (Brodmann area 7), right inferior occipital gyrus (Brodmann area 18), left cerebellar lobule IX and Crus II, right cerebellar lobule VIIIA, and right Crus I. Of note, many brain voxels that are selective for ASD include areas that are posterior components of the default mode network.

CONCLUSIONS

The identification of these spatial gray matter alteration patterns offers new insights into understanding the complex neurobiological underpinnings of ASD and opens attractive prospects for future neuroimaging-based interventions.

Promoting Low-Carbon Purchase from Social Norms Perspective

The importance of individual consumption behavior in a low-carbon economy is gradually recognized. Social norms have a significant effect on individual purchase behavior. However, the influence mechanism of social norms still needs more research. We conducted two behavioral experiments to explore the specific factors: first, the effect of descriptive norms on personal low-carbon consumption behavior through feedback information, and second, a comparison with injunctive norms, focusing on the impact of the normative focus shift brought by punishment represented by the policy implementation. The results show that social norms can effectively promote individual low-carbon consumption through feedback and high policy implementation efficiency. In particular, after effective policy implementation becomes an inherent element of injunctive norms, injunctive norms are activated and become the focus of norms, significantly improving the purchase rate of low-carbon goods.

Distinctive Roles of Medial Prefrontal Cortex Subregions in Strategic Conformity to Social Hierarchy

People often align their behaviors and decisions with others' expectations, especially those of higher social positions, when they are being observed. However, little attention has been paid to the neural mechanisms underlying increased conformity to the social hierarchy under social observation. Using a preference rating task, we investigated whether and how individual preferences for novel stimuli were influenced by others' preferences by manipulating others' social hierarchy and observational context. The behavioral results showed that human participants of both sexes were more likely to change their preferences to match those of a superior partner in a public than in a private context. fMRI data revealed distinct contributions of the subregions of the medial prefrontal cortex (mPFC) to increased conformity to social hierarchy under observation. Specifically, the ventral mPFC showed increased activity when participants' preferences aligned with those of superior partners, regardless of behavioral manifestation. The rostral mPFC showed increased activity when conforming to a superior partner and nonconforming to an inferior one, indicating goal-dependent valuation. The dorsal mPFC showed increased activity in private conditions with a superior partner but only in those with a higher tendency to conform. These findings support the hierarchical allostatic regulation model of the mPFC function for social valuation and suggest strategic conformity as a way to minimize metabolic costs.SIGNIFICANCE STATEMENT This study revealed distinct roles of subregions of the mPFC in increased conformity to individuals of different social ranks under observation. Specifically, the ventral mPFC showed increased activity when participants' preferences aligned with those of higher-ranking partners, whereas the rostral mPFC showed increased activity when conforming to a superior partner and nonconforming to an inferior partner, indicating goal-dependent valuation. The dorsal mPFC was more active in private conditions with a superior partner but only in those with a higher tendency to conform. These findings support the hierarchical allostatic regulation model of the mPFC function for social valuation and suggest strategic conformity as a way to minimize metabolic costs.

Individual differences in gaze-cuing effect are associated with facial emotion recognition and social conformity

Spontaneous gaze following and the concomitant joint attention enable us to share representations of the world with others, which forms a foundation of a broad range of social cognitive processes. Although this form of social orienting has long been suggested as a critical starting point for the development of social and communicative behavior, there is limited evidence directly linking it to higher-level social cognitive processes among healthy adults. Here, using a gaze-cuing paradigm, we examined whether individual differences in gaze following tendency predict higher-order social cognition and behavior among healthy adults. We found that individuals who showed greater gaze-cuing effect performed better in recognizing others' emotion and had greater tendency to conform with group opinion. These findings provide empirical evidence supporting the fundamental role of low-level socio-attentional processes in human sociality.

Be Careful When Using Peer-Influence on Nudging Solicitation: Evidence of Potential Negative Effect from a Sample of Chinese University Students

PURPOSE

Peer information is now commonly used in solicitation. However, scholars have long focused on testing its effectiveness on increasing the donation amount without paying attention to its potential negative effects on donors. Thus, the current study employs high vs low peer donation amount (HPDA vs LPDA) information to explore its effect on "how-much-to-donate" decisions and the corresponding neural and psychological reactions at the same time.

PARTICIPANTS AND METHODS

Student samples from a Chinese university and behavioral experiments with the event-related potential (ERP) method were used in this study.

RESULTS

The behavioral results are consistent with previous research in which HPDA was positively associated with higher donation levels. ERP results show the mechanisms behind decision-making can be summarized into a cognitive approach represented by cost-benefit analysis and an affective approach represented by reward perception. More surprisingly, in contrast to the behavioral results, LPDA elicits higher level of reward perception than HPDA.

CONCLUSION

The results indicate that although HPDA leads to higher levels of donation, donors do not show higher levels of reward anticipation at the neurological level, indicating the increment of donation may come at the cost of donors. Theoretical and practical implications are also discussed.

Intra- and inter-brain synchrony oscillations underlying social adjustment

Humans naturally synchronize their behavior with other people. However, although it happens almost automatically, adjusting behavior and conformity to others is a complex phenomenon whose neural mechanisms are still yet to be understood entirely. The present experiment aimed to study the oscillatory synchronization mechanisms underlying automatic dyadic convergence in an EEG hyperscanning experiment. Thirty-six people performed a cooperative decision-making task where dyads had to guess the correct position of a point on a line. A reinforcement learning algorithm was used to model different aspects of the participants' behavior and their expectations of their peers. Intra- and inter-connectivity among electrode sites were assessed using inter-site phase clustering in three main frequency bands (theta, alpha, beta) using a two-level Bayesian mixed-effects modeling approach. The results showed two oscillatory synchronization dynamics related to attention and executive functions in alpha and reinforcement learning in theta. In addition, inter-brain synchrony was mainly driven by beta oscillations. This study contributes preliminary evidence on the phase-coherence mechanism underlying inter-personal behavioral adjustment.

How we learn social norms: a three-stage model for social norm learning

As social animals, humans are unique to make the world function well by developing, maintaining, and enforcing social norms. As a prerequisite among these norm-related processes, learning social norms can act as a basis that helps us quickly coordinate with others, which is beneficial to social inclusion when people enter into a new environment or experience certain sociocultural changes. Given the positive effects of learning social norms on social order and sociocultural adaptability in daily life, there is an urgent need to understand the underlying mechanisms of social norm learning. In this article, we review a set of works regarding social norms and highlight the specificity of social norm learning. We then propose an integrated model of social norm learning containing three stages, i.e., pre-learning, reinforcement learning, and internalization, map a potential brain network in processing social norm learning, and further discuss the potential influencing factors that modulate social norm learning. Finally, we outline a couple of future directions along this line, including theoretical (i.e., societal and individual differences in social norm learning), methodological (i.e., longitudinal research, experimental methods, neuroimaging studies), and practical issues.

Neural Basis of Social Influence of Observing Other's Perception in Dot-Number Estimation

Our perceptions and decisions are often implicitly influenced by observing another's actions. However, it is unclear how observing other people's perceptual decisions without interacting with them can engage the processing of self-other discrepancies and change the observer's decisions. In this study, we employed functional magnetic resonance imaging and a computational model to investigate the neural basis of how unilaterally observing the other's perceptual decisions modulated one's own decisions. The experimental task was to discriminate whether the number of presented dots was higher or lower than a reference number. The participants performed the task solely while unilaterally observing the performance of another "participant," who produced overestimations and underestimations in the same task in separate sessions. Results of the behavioral analysis showed that the participants' decisions were modulated to resemble those of the other. Image analysis based on computational model revealed that the activation in the medial prefrontal cortex was associated with the discrepancy between the inferred participant's and the presented other's decisions. In addition, the number-sensitive region in the superior parietal region showed altered activation patterns after observing the other's overestimations and underestimations. The activity of the superior parietal region was not involved in assessing the observation of other's perceptual decisions, but it was engaged in plain numerosity perception. These results suggest that computational modeling can capture the neuro-behavioral processing of self-other discrepancies in perception followed by the activity modulation in the number-sensitive region in the task of dot-number estimation.

Neural correlates associated with conformity in adolescent and young adult men

Social influence affects us throughout our lives, shaping our attitudes, behaviors, and preferences. Thus, the current study aimed to examine whether key age groups (adolescence versus young adulthood) were associated with differences in neural correlates associated with processing social feedback and conformity (i.e., conflict detection, positive valuation, and mentalizing) among young men. We recruited 153 participants across 5 studies, who completed a social influence task during an fMRI scan. Overall, participants were more likely to conform by changing their ratings when misaligned with others, and adolescents were more likely to conform when misaligned (compared to aligned) with others compared to young adults. Further, we found that adolescents showed increased activity in mentalizing (TPJ, dmPFC) and positive valuation regions (VS, vmPFC), compared to young adults, in response to misalignment with others. In contrast, young adults showed increased activity in conflict detection regions (AI, dACC) when exposed to feedback that they were misaligned with others and when conforming to that feedback. Overall, our results offer initial evidence that adolescent and young adult men engage different neural processes when they find out they are misaligned with others and when conforming to the recommendations of others, and this difference appears to track with brain responses in conflict detection, mentalizing and value regions. DATA STATEMENT: Raw data and analysis codes are available upon request.

Social conformity is associated with inter-trial electroencephalogram variability

Human society encompasses diverse social influences, and people experience events differently and may behave differently under such influence, including in forming an impression of others. However, little is known about the underlying neural relevance of individual differences in following others' opinions or social norms. In the present study, we designed a series of tasks centered on social influence to investigate the underlying relevance between an individual's degree of social conformity and their neural variability. We found that individual differences under the social influence are associated with the amount of inter-trial electroencephalogram (EEG) variability over multiple stages in a conformity task (making face judgments and receiving social influence). This association was robust in the alpha band over the frontal and occipital electrodes for negative social influence. We also found that inter-trial EEG variability is a very stable, participant-driven internal state measurement and could be interpreted as mindset instability. Overall, these findings support the hypothesis that higher inter-trial EEG variability may be related to higher mindset instability, which makes participants more vulnerable to exposed external social influence. The present study provides a novel approach that considers the stability of one's endogenous neural signal during tasks and links it to human social behaviors.

Social value orientation modulates behavioral and neural responses to social influence

Substantial studies have investigated the social influence effect; however, how individuals with different social value orientations (SVOs), prosocials and proselfs, respond to different social influences remains unknown. This study examines the impact of positive and negative social information on the responses of people with different SVOs. A face-attractiveness assessment task was employed to investigate the relationships between influence probability, memory, and event-related potentials of social influence. A significant interactional effect suggested that prosocials and proselfs reacted differently to positive (group rating was more attractive) and negative (group rating was less attractive) social influences. Specifically, proselfs demonstrated significantly higher influence probability, marginally better recall performance, smaller N400, and larger late positive potential on receiving negative influence information than on receiving positive influence information, while prosocials showed no significant differences. Overall, correlations between N400/LPP, influence probability, and recall performance were significant. The above results indicate the modulating role of SVO when responding to social influence. These findings have important implications for understanding how people conform and how prosocial behavior occurs.

Brain Systems Underlying Fundamental Motivations of Human Social Conformity

From birth to adulthood, we often align our behaviors, attitudes, and opinions with a majority, a phenomenon known as social conformity. A seminal framework has proposed that conformity behaviors are mainly driven by three fundamental motives: a desire to gain more information to be accurate, to obtain social approval from others, and to maintain a favorable self-concept. Despite extensive interest in neuroimaging investigation of social conformity, the relationship between brain systems and these fundamental motivations has yet to be established. Here, we reviewed brain imaging findings of social conformity with a componential framework, aiming to reveal the neuropsychological substrates underlying different conformity motivations. First, information-seeking engages the evaluation of social information, information integration, and modification of task-related activity, corresponding to brain networks implicated in reward, cognitive control, and tasks at hand. Second, social acceptance involves the anticipation of social acceptance or rejection and mental state attribution, mediated by networks of reward, punishment, and mentalizing. Third, self-enhancement entails the excessive representation of positive self-related information and suppression of negative self-related information, ingroup favoritism and/or outgroup derogation, and elaborated mentalizing processes to the ingroup, supported by brain systems of reward, punishment, and mentalizing. Therefore, recent brain imaging studies have provided important insights into the fundamental motivations of social conformity in terms of component processes and brain mechanisms.

People conform to social norms when gambling with lives or money

Many consider moral decisions to follow an internal "moral compass", resistant to social pressures. Here we examine how social influence shapes moral decisions under risk, and how it operates in different decision contexts. We employed an adapted Asian Disease Paradigm where participants chose between certain losses/gains and probabilistic losses/gains in a series of moral (lives) or financial (money) decisions. We assessed participants' own risk preferences before and after exposing them to social norms that are generally risk-averse or risk-seeking. Our results showed that participants robustly shifted their own choices towards the observed risk preferences. This conformity holds even after a re-testing in three days. Interestingly, in the monetary domain, risk-averse norms have more influence on choices in the loss frame, whereas risk-seeking norms have more influence in the gain frame, presumably because norms that contradict default behavior are most informative. In the moral domain, risk-averse as opposed to risk-seeking norms are more effective in the loss frame but in the gain frame different norms are equally effective. Taken together, our results demonstrate conformity in risk preferences across contexts and highlight unique features of decisions and conformity in moral and monetary domains.

Group polarization calls for group-level brain communication

Group of people shows the shift towards extreme of decision-making as opposed to individuals. Previous studies have revealed two directions of group polarization, i.e., risky shift and cautious shift, but how group of brains drive these shifts remains unknown. In the current study, we arranged risk advantage and disadvantage situations to elicit group polarization of risky shift and cautious shift respectively, and examined the averaged inter-brain synchronization (ABS) among participant triads during group decision making versus individual decision making. The elicited group polarizations were accompanied by the enhanced ABS at bilateral prefrontal areas and left temporoparietal junction (TPJ). Specifically, the TPJ ABS was equivalent in risky shift and cautious shift, and based on machine learning analyses, could predict the extent of group polarization; for two shifts, it negatively correlated with negative emotion. However, the right prefrontal ABS was stronger in risky shift than in cautious shift, and the same area showed the larger brain deactivation in former shift, indicating weaker executive control. For the left prefrontal ABS, only the equivalent ABS was found for two shifts. In sum, group polarization of risky shift and cautious shift calls for inter-brain communication at the group level, and the former shift is with deactivation and more brain synchronization. Our study suggests emotional and cognitive adjustment in decision making of the group compared with individuals.

How do children adapt their fairness norm? Evidence from computational modeling

Adequate social functioning during childhood requires context-appropriate social decision-making. To make such decisions, children rely on their social norms, conceptualized as cognitive models of shared expectations. Since social norms are dynamic, children must adapt their models of shared expectations and modify their behavior in line with their social environment. This study aimed to investigate children's abilities to use social information to adapt their fairness norm and to identify the computational mechanism governing this process. Thirty children (7-11 years, M = 7.9 SD = 0.85, 11 girls) played the role of Responder in a modified version of the Ultimatum Game-a two-player game based on the fairness norm-in which they had to choose to accept or reject offers from different Proposers. Norm adaptation was assessed by comparing rejection rates before and after a conditioning block in which children received several low offers. Computational models were compared to test which best explains children's behavior during the game. Mean rejection rate decreased significantly after receiving several low offers suggesting that children have the ability to dynamically update their fairness norm and adapt to changing social environments. Model-based analyses suggest that this process involves the computation of norm-prediction errors. This is the first study on norm adaptation capacities in school-aged children that uses a computational approach. Children use implicit social information to adapt their fairness norm to changing environments and this process appears to be supported by a computational mechanism in which norm-prediction errors are used to update norms.

Neural implementation of computational mechanisms underlying the continuous trade-off between cooperation and competition

Social interactions evolve continuously. Sometimes we cooperate, sometimes we compete, while at other times we strategically position ourselves somewhere in between to account for the ever-changing social contexts around us. Research on social interactions often focuses on a binary dichotomy between competition and cooperation, ignoring people's evolving shifts along a continuum. Here, we develop an economic game - the Space Dilemma - where two players change their degree of cooperativeness over time in cooperative and competitive contexts. Using computational modelling we show how social contexts bias choices and characterise how inferences about others' intentions modulate cooperativeness. Consistent with the modelling predictions, brain regions previously linked to social cognition, including the temporo-parietal junction, dorso-medial prefrontal cortex and the anterior cingulate gyrus, encode social prediction errors and context-dependent signals, correlating with shifts along a cooperation-competition continuum. These results provide a comprehensive account of the computational and neural mechanisms underlying the continuous trade-off between cooperation and competition.

Shared understanding and social connection: Integrating approaches from social psychology, social network analysis, and neuroscience

Meaningfully connecting with others is critical to the well-being of individuals. What phenomena contribute to and stem from social connection? In this paper, we integrate emerging work that uses neuroimaging and social network analysis with theories that explore the links between shared reality and social connection. We highlight recent work suggesting that the extent to which people have aligned mental processing and shared subjective construals to those around them-as shown by neural similarity-is associated with both objective and subjective social connection. On the other hand, idiosyncrasies are linked to difficulties with social connection. We conclude by suggesting how the links between shared understanding and social connection can be productively used as a framework to study psychosocial phenomena of interest.

Modelling Spirals of Silence and Echo Chambers by Learning from the Feedback of Others

What are the mechanisms by which groups with certain opinions gain public voice and force others holding a different view into silence? Furthermore, how does social media play into this? Drawing on neuroscientific insights into the processing of social feedback, we develop a theoretical model that allows us to address these questions. In repeated interactions, individuals learn whether their opinion meets public approval and refrain from expressing their standpoint if it is socially sanctioned. In a social network sorted around opinions, an agent forms a distorted impression of public opinion enforced by the communicative activity of the different camps. Even strong majorities can be forced into silence if a minority acts as a cohesive whole. On the other hand, the strong social organisation around opinions enabled by digital platforms favours collective regimes in which opposing voices are expressed and compete for primacy in public. This paper highlights the role that the basic mechanisms of social information processing play in massive computer-mediated interactions on opinions.

Enhanced endogenous oxytocin signaling in the brain modulates neural responses to social misalignment and promotes conformity in humans: A multi-locus genetic profile approach

The neuropeptide oxytocin (OT) is known to promote social conformity. However, the specific neurocognitive mechanisms underlying OT-induced conformity remain unclear. We aimed to address this gap by examining how genetic variation in the oxytocin receptor gene (OXTR) is linked with behavioral conformity and its underlying neural systems. Specifically, we utilized the genotype-tissue expression database (GTEx) to create a novel multi-locus genetic profile score (MPS) that reflects the level of OXTR expression in the human brain. A total of 194 participants (Neuroimaging N = 50, Behavioral N = 144) performed a novel conformity task in which they viewed a series of word pairs depicting various moral values and virtues widely recognized in the United States. In each trial, participants indicated the relative importance of these words and subsequently learned about the majority opinion. Participants later rated the same word pairs a second time. Changes in participants' ratings between the first and second sessions were measured and analyzed with respect to social feedback, blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) signals, and OXTR MPS. We found that participants adjusted their ratings in accordance with the majority opinions. Social misalignment between self and others activated brain areas such as the striatum and the posterior medial frontal cortex (pMFC). However, unlike most findings from previous studies, activation in the pMFC during the inconsistent social feedback negatively, rather than positively, predicted behavioral conformity. Notably, those with higher OXTR MPS had reduced pMFC activation in the face of social misalignment, which led to greater conformity. Our findings suggest that OT may promote conformity by dampening the conflict-related signals in the pMFC. They also show that OXTR MPS may be useful for studying the effect of genes on highly complex human social traits, such as conformity.

Brain dynamics of recommendation-based social influence on preference change: A magnetoencephalography study

People change their preferences when exposed to others' opinions. We examine the neural basis of how peer feedback influences an individual's recommendation behavior. In addition, we investigate if the personality trait of 'agreeableness' modulates behavioral change and neural responses. In our experiment, participants with low and high agreeableness indicated their degree of recommendation of commercial brands, while subjected to peer group feedback. The associated neural responses were recorded with concurrent magnetoencephalography. After a delay, the participants were asked to reevaluate the brands. Recommendations changed consistently with conflicting feedback only when peer recommendation was lower than the initial recommendation. On the neural level, feedback evoked neural responses in the medial frontal and lateral parietal cortices, which were stronger for conflicting peer opinions. Conflict also increased neural oscillations in 4-10 Hz and decreased oscillations in 13-30 Hz in medial frontal and parietal cortices§. The change in recommendation behavior was not different between the low and high agreeableness groups. However, the groups differed in neural oscillations in the alpha and beta bands, when recommendation matched with feedback. In addition to corroborating earlier findings on the role of conflict monitoring in feedback processing, our results suggest that agreeableness modulates neural processing of peer feedback.

Social learning across adolescence: A Bayesian neurocognitive perspective

Adolescence is a period of social re-orientation in which we are generally more prone to peer influence and the updating of our beliefs based on social information, also called social learning, than in any other stage of our life. However, how do we know when to use social information and whose information to use and how does this ability develop across adolescence? Here, we review the social learning literature from a behavioral, neural and computational viewpoint, focusing on the development of brain systems related to executive functioning, value-based decision-making and social cognition. We put forward a Bayesian reinforcement learning framework that incorporates social learning about value associated with particular behavior and uncertainty in our environment and experiences. We discuss how this framework can inform us about developmental changes in social learning, including how the assessment of uncertainty and the ability to adaptively discriminate between information from different social sources change across adolescence. By combining reward-based decision-making in the domains of both informational and normative influence, this framework explains both negative and positive social peer influence in adolescence.

Social norm learning from non-human agents can induce a persistent perceptual bias: A diffusion model approach

Seminal studies on social influence (Asch, 1956; Sherif, 1935) were based on face-to-face interactions between humans. Nowadays, computer-mediated communication is steadily becoming ubiquitous, and we are increasingly influenced by non-human agents, such as algorithms, robots, and chatbots. The present research aimed to answer two important questions: Can non-human agents exert social influence in a persistent manner and, thus, contribute to the emergence of social norms? And if this is the case, is social influence exerted by non-human agents mediated by the same or by different cognitive mechanisms as social influence exerted by human agents? To answer these questions, we used an online version of an established paradigm in research on social norm learning. To examine the cognitive underpinnings of social influence, we used a diffusion model approach. Our results provide strong evidence for the notion that non-human agents can induce persistent social influence outside an immediate group context and, hence, can contribute to the emergence of social norms. Furthermore, results from our diffusion model analyses support the notion that social influence exerted by non-human agents is mainly mediated by the same cognitive mechanisms as social influence exerted by human agents.

When the Counterpart Chooses the Opposite: The First Mover’s Anticipation and Evaluation of the Final Feedback in Gambles

This research examines the effect of response (in) consistency on the first mover’s anticipation and evaluation of the performance feedback in gambles. In a two-player gambling task, the participant played as the first mover while the confederate served as the second mover, who made their gambles in sequence. A more pronounced feedback-related negativity (FRN) was observed when the first mover noticed that the second mover chose a different option from him/her. An enlarged stimulus-preceding negativity (SPN) was observed when the first mover was anticipating the final feedback in this condition. Interestingly, consistent responses gave rise to a more pronounced FRN difference wave (d-FRN) during the feedback stage. Taken together, these results suggest that response discrepancy would modulate the first mover’s anticipation and evaluation of the final feedback in gambles.

Cost-benefit considerations have limited effect on the decision to exert cognitive effort in real-world computer-programming tasks

Recent research shows that people usually try to avoid exerting cognitive effort yet they are willing to exert effort to gain rewards. This cost-benefit framework provides predictions for behaviour outside the laboratory. Nevertheless, the extent to which such considerations affect real-life decisions is not clear. Here we experimentally examined computer-programmers' decisions to write code in a reusable manner, using functions, which demands an initial investment of cognitive effort or to clone and tweak code, a strategy whose cost increases with repetitions. Only a small portion of our participants demonstrated sensitivity to the benefits and costs of programming strategies. When asked to solve the tasks, participants tended to avoid using functions, demonstrating biased effort estimation. By contrast, when asked how they planned to solve the tasks, participants tended to demonstrate an opposite trend, overestimating effort, in line with an injunctive norm involving the overuse of functions. In the context of real-world problems, the effect of cost-benefit considerations may therefore be limited by task-irrelevant factors. Our interdisciplinary approach may be useful in providing novel theoretical insights and in promoting cognitive-effort investments outside the laboratory.

Learning under social versus nonsocial uncertainty: A meta-analytic approach

Much of the uncertainty that clouds our understanding of the world springs from the covert values and intentions held by other people. Thus, it is plausible that specialized mechanisms that compute learning signals under uncertainty of exclusively social origin operate in the brain. To test this hypothesis, we scoured academic databases for neuroimaging studies involving learning under uncertainty, and performed a meta‐analysis of brain activation maps that compared learning in the face of social versus nonsocial uncertainty. Although most of the brain activations associated with learning error signals were shared between social and nonsocial conditions, we found some evidence for functional segregation of error signals of exclusively social origin during learning in limited regions of ventrolateral prefrontal cortex and insula. This suggests that most behavioral adaptations to navigate social environments are reused from frontal and subcortical areas processing generic value representation and learning, but that a specialized circuitry might have evolved in prefrontal regions to deal with social context representation and strategic action.

Blend in or stand out: social anxiety levels shape information-sharing strategies

Although living in social groups provides many benefits for group members, such groups also serve as a setting for social competition over rank and influence. Evolutionary accounts suggest that social anxiety plays a role in regulating in-group conflict, as individuals who are concerned about social threat may choose to defer to others to maintain the hierarchical status quo. Here, we examine how social anxiety levels are related to the advice-giving style an individual adopts: a competitive influence-seeking strategy or a defensive blend-in strategy. We begin by demonstrating that similarity to others drives activity in the brain's valuation system, even during a competitive advice-taking task. Then, in three behavioural experiments, we show that social anxiety levels are related to the tendency to give advice resembling the advice given by rival advisers and to refrain from status-seeking behaviour. Social anxiety was also associated with negative social comparisons with rival advisers. Our findings highlight the role of competing social goals in shaping information sharing.

Did It Change Your Mind? Neural Substrates of Purchase Intention Change and Product Information

Price and customer ratings are perhaps the two most important pieces of information consumers rely on when shopping online. This study aimed to elucidate the neural mechanism by which the introduction of these two types of information influences the purchase intention of potential consumers for hedonic products. Participants performed a lip-care product shopping task during functional magnetic resonance imaging, in which they re-disclosed purchase intentions referring to the information of price or rating provided about the products that they had previously disclosed their purchase intentions without any information. Data from 38 young female participants were analyzed to identify the underlying neural regions associated with the intention change and product information. The bilateral frontopolar cortex, bilateral dorsal anterior cingulate cortex (dACC), and left insula activated higher for the unchanged than changed intention condition. The right dACC and bilateral insula also activated more toward the price than the rating condition, whereas the medial prefrontal cortex and bilateral temporoparietal junction responded in the opposite direction. These results seem to reflect the shift to exploratory decision-making strategies and increased salience in maintaining purchase intentions despite referring to provided information and to highlight the involvement of social cognition-related regions in reference to customer ratings rather than price.

Prefrontal control of social influence in risk decision making

To optimize our decisions, we may change our mind by utilizing social information. Here, we examined how changes of mind were modulated by Social Misalignment Sensitivity (SMS), egocentric tendency, and decision preferences in a decision-making paradigm including both risk and social information. Combining functional magnetic resonance imaging with computational modeling, we showed that both SMS and egocentric tendency modulated changes of mind under the influence of social information. While SMS was represented in the dorsal anterior cingulate cortex (dACC) and superior parietal gyrus (SPG) in the socially aligned situation, a distributed brain network was activated in the misaligned condition, including not only the dACC and SPG but also superior frontal gyrus and precuneus. These results suggest that SMS is related to a monitoring brain system, the scope of which varies according to the level of misalignment with social majority. The dorsolateral prefrontal cortex selectively interacted with SMS among the participants with a low switching threshold, indicating that its regulation on SMS may be sensitive to inter-individual variation. Our findings highlight the predominant roles of SMS and the prefrontal control system towards changes of mind under social influence.

Dopaminergic challenge dissociates learning from primary versus secondary sources of information

Some theories of human cultural evolution posit that humans have social-specific learning mechanisms that are adaptive specialisations moulded by natural selection to cope with the pressures of group living. However, the existence of neurochemical pathways that are specialised for learning from social information and individual experience is widely debated. Cognitive neuroscientific studies present mixed evidence for social-specific learning mechanisms: some studies find dissociable neural correlates for social and individual learning, whereas others find the same brain areas and, dopamine-mediated, computations involved in both. Here, we demonstrate that, like individual learning, social learning is modulated by the dopamine D2 receptor antagonist haloperidol when social information is the primary learning source, but not when it comprises a secondary, additional element. Two groups (total N = 43) completed a decision-making task which required primary learning, from own experience, and secondary learning from an additional source. For one group, the primary source was social, and secondary was individual; for the other group this was reversed. Haloperidol affected primary learning irrespective of social/individual nature, with no effect on learning from the secondary source. Thus, we illustrate that dopaminergic mechanisms underpinning learning can be dissociated along a primary-secondary but not a social-individual axis. These results resolve conflict in the literature and support an expanding field showing that, rather than being specialised for particular inputs, neurochemical pathways in the human brain can process both social and non-social cues and arbitrate between the two depending upon which cue is primarily relevant for the task at hand.

A neurobiological perspective on social influence: Serotonin and social adaptation

Humans are inherently social beings. Being suggestible to each other's expectations enables pro-social skills that are crucial for social learning and adaptation. Despite its high relevance for psychiatry, the neurobiological mechanisms underlying social adaptation are still not well understood. This review therefore provides a conceptual framework covering various distinct mechanisms underlying social adaptation and explores the neuropharmacology - in particular the role of the serotonin (5-HT) system - modulating these mechanisms. This article therefore reviews empirical results on social influence processing and reconciles them with recent findings from psychedelic research on social processing to elucidate neurobiological and neuropharmacological underpinnings of social adaptation. Various computational, neurobiological, and neurochemical processes are involved in distinct mechanisms underlying social adaptation such as the multisensory process of social information integration that is crucial for the forming of self-representation and representations of social norms. This is again associated with self- and other-perception during social interactions as well as value-based decision making that guides our behaviour in daily interactions. We highlight the critical role of 5-HT in these processes and suggest that 5-HT can facilitate social learning and may represent an important target for treating psychiatric disorders characterized by impairments in social functioning. This framework also has important implications for psychedelic-assisted therapy as well as for the development of novel treatment approaches and future research directions.

Distinct neurocomputational mechanisms support informational and socially normative conformity

A change of mind in response to social influence could be driven by informational conformity to increase accuracy, or by normative conformity to comply with social norms such as reciprocity. Disentangling the behavioural, cognitive, and neurobiological underpinnings of informational and normative conformity have proven elusive. Here, participants underwent fMRI while performing a perceptual task that involved both advice-taking and advice-giving to human and computer partners. The concurrent inclusion of 2 different social roles and 2 different social partners revealed distinct behavioural and neural markers for informational and normative conformity. Dorsal anterior cingulate cortex (dACC) BOLD response tracked informational conformity towards both human and computer but tracked normative conformity only when interacting with humans. A network of brain areas (dorsomedial prefrontal cortex (dmPFC) and temporoparietal junction (TPJ)) that tracked normative conformity increased their functional coupling with the dACC when interacting with humans. These findings enable differentiating the neural mechanisms by which different types of conformity shape social changes of mind.

Mine or Ours? Neural Basis of the Exploitation of Common-Pool Resources

Why do people often exhaust unregulated common (shared) natural resources but manage to preserve similar private resources? To answer this question, in this study we combine a neurobiological, economic and cognitive modeling approach. Using functional magnetic resonance imaging on 50 participants, we show that a sharp decrease of common and private resources is associated with deactivation of the ventral striatum, a brain region involved in the valuation of outcomes. Across individuals, when facing a common resource, ventral striatal activity is anticorrelated with resource preservation (less harvesting), whereas with private resources the opposite pattern is observed. This indicates that neural value signals distinctly modulate behavior in response to the depletion of common vs private resources. Computational modeling suggested that overharvesting of common resources was facilitated by the modulatory effect of social comparison on value signals. These results provide an explanation of people’s tendency to over-exploit unregulated common natural resources.