Groupie
The Social Sense: Susceptibility to Others' Beliefs in Human Infants and Adults
Ágnes Melinda Kovács, Ernő Téglás & Ansgar Denis Endress
Science, 24 December 2010, Pages 1830-1834
Abstract:
Human social interactions crucially depend on the ability to represent other agents' beliefs even when these contradict our own beliefs, leading to the potentially complex problem of simultaneously holding two conflicting representations in mind. Here, we show that adults and 7-month-olds automatically encode others' beliefs, and that, surprisingly, others' beliefs have similar effects as the participants' own beliefs. In a visual object detection task, participants' beliefs and the beliefs of an agent (whose beliefs were irrelevant to performing the task) both modulated adults' reaction times and infants' looking times. Moreover, the agent's beliefs influenced participants' behavior even after the agent had left the scene, suggesting that participants computed the agent's beliefs online and sustained them, possibly for future predictions about the agent's behavior. Hence, the mere presence of an agent automatically triggers powerful processes of belief computation that may be part of a "social sense" crucial to human societies.
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Ali Ahmed & Osvaldo Salas
Journal of Socio-Economics, forthcoming
Abstract:
We investigate how implicit influences of Christian religious representations affect prosociality. We examine the direct impact of religion as an independent variable on prosocial behavior. We do so by priming participants with religious words in a scrambled sentence task before they make a dictator game and a prisoner's dilemma game decision. Priming religious words significantly increased prosocial behavior in both games: Participants in the treatment group were more generous and cooperative than participants in the control group. The priming effect was present regardless of participants' self-reported religiosity. Self-reported religiosity was not correlated with generosity or cooperation.
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Young Children Share the Spoils After Collaboration
Felix Warneken, Karoline Lohse, Alicia Melis & Michael Tomasello
Psychological Science, forthcoming
Abstract:
Egalitarian behavior is considered to be a species-typical component of human cooperation. Human adults tend to share resources equally, even if they have the opportunity to keep a larger portion for themselves. Recent experiments have suggested that this tendency emerges fairly late in human ontogeny, not before 6 or 7 years of age. Here we show that 3-year-old children share mostly equally with a peer after they have worked together actively to obtain rewards in a collaboration task, even when those rewards could easily be monopolized. These findings contrast with previous findings from a similar experiment with chimpanzees, who tended to monopolize resources whenever they could. The potentially species-unique tendency of humans to share equally emerges early in ontogeny, perhaps originating in collaborative interactions among peers.
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Moral Judgments in Social Dilemmas: How Bad is Free Riding?
Robin Cubitt, Michalis Drouvelis, Simon Gächter & Ruslan Kabalin
Journal of Public Economics, forthcoming
Abstract:
In the last thirty years, economists and other social scientists have investigated people's normative views on distributive justice. Here we study people's normative views in social dilemmas, which underlie many situations of economic and social significance. Using insights from moral philosophy and psychology we provide an analysis of the morality of free riding. We use experimental survey methods to investigate people's moral judgments empirically. We vary others' contributions, the framing ("give-some" vs. "take-some") and whether contributions are simultaneous or sequential. We find that moral judgments of a free rider depend strongly on others' behaviour; and that failing to give is condemned more strongly than withdrawing all support.
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Cultivating Trust: Norms, Institutions and the Implications of Scale
Chris Bidner & Patrick Francois
Economic Journal, forthcoming
Abstract:
We study the co-evolution of honesty norms and institutions. New trading opportunities require institutional changes to be realised, since the initial vulnerability of institutions to opportunistic behaviour leads to the deterioration of norms. We show how an escape from opportunism requires that institutional improvements outpace norm deterioration. A key prediction emerges: larger economies are more likely to evolve to steady states with strong honesty norms but need not have better institutions. This prediction is tested using a cross-section of countries; population has a significant positive relationship with trust, even when controlling for standard trust determinants and institutional quality.
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The gaze that grooms: Contribution of social factors to the evolution of primate eye morphology
Hiromi Kobayashi & Kazuhide Hashiya
Evolution and Human Behavior, forthcoming
Abstract:
There is a wide variation in the external eye morphology across species in primates, which is considered to reflect adaptation to ecological factors such as body size and habitat type. However, little attention has been paid to the contribution of social factors to the evolution of primate eye morphology. To explore this, we analyzed correlations among eye morphology, social factors (neocortex ratio and group size) and other factors (habitat type and body mass) in 30 living primate species including humans, using phylogenetically independent contrasts. The results indicated that parameters of primate eye morphology correlate with group size and neocortex ratio (Study 1). Further analysis of behavior indicated that the proportion of scanning with eyeball movement alone per total scanning correlated with group size and neocortex ratio (Study 2). The results support the view that the scanning with independent eyeball movement and its morphological basis is an adaptation to larger social groups. Communicative functions of the gaze signal other than the expression of aggression, observed in some primate species, may be based on features related to eye morphology. Furthermore, the evolution of a contact-free, social grooming function of gaze, especially predominant in humans, may reflect one extreme case of this kind of adaptation, which we call the "gaze-grooming" hypothesis.
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Elevation predicts domain-specific volunteerism 3 months later
Keith Cox
Journal of Positive Psychology, September 2010, Pages 333-341
Abstract:
Elevation, the feeling of moral uplift when viewing the virtuous action of another, has been shown to be a distinct moral emotion [Algoe, S.B., & Haidt, J. (2009). Witnessing excellence in action: The 'other-praising' emotions of elevation, gratitude, and admiration. Journal of Positive Psychology, 4, 105-127]. Prosocial behaviors have been theorized to be one of the behavioral effects of elevation, but this behavioral connection has not been strongly established. This study followed college students in a naturalistic setting known to induce elevation, a spring break service trip. Self-reports of elevation during service trip were collected from participants at the conclusion of the trip. At 1 week and 3 months later, participants reported on trip-related and general volunteerism. Self-reports of elevation during the trip predicted trip-specific volunteerism at 1 week and 3 months, but did not relate to general volunteerism at either time. This predictive connection was maintained even when pre-trip volunteerism, trait empathy, and the dispositions of Extraversion, Openness to Experience, and Agreeableness were controlled for. These results suggest that the experience of elevation motivated participants to volunteer in the domain in which they felt elevation. This finding supports the hypothesis that prosocial responses are a behavioral effect of elevation, but further refines this hypothesis by suggesting that the prosocial response occurs in a domain linked to the context in which elevation was experienced.
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Does social capital matter? Evidence from a five-country group lending experiment
Alessandra Cassar & Bruce Wydick
Oxford Economic Papers, October 2010, Pages 715-739
Abstract:
Does social capital matter to economic decision-making? We address this broad question through an artefactual group lending experiment carried out in five countries: India, Kenya, Guatemala, Armenia, and the Philippines, obtaining data on 10,673 contribution decisions from 1,554 subjects in 259 experimental borrowing groups. We carry out treatments for social homogeneity, group monitoring, and borrowing group self-selection. Results show that societal trust positively and significantly influences group loan contribution rates, that group lending appears to create as well as harness social capital, and that peer monitoring can have perverse as well as beneficial effects.
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An fMRI investigation of empathy for 'social pain' and subsequent prosocial behavior
Carrie Masten, Sylvia Morelli & Naomi Eisenberger
NeuroImage, forthcoming
Abstract:
Despite empathy's importance for promoting social interactions, neuroimaging research has largely overlooked empathy during social experiences. Here, we examined neural activity during empathy for social exclusion and assessed how empathy-related neural processes might relate to subsequent prosocial behavior toward the excluded victim. During an fMRI scan, participants observed one person being excluded by two others, and afterwards sent emails to each of these 'people.' Later, a group of raters assessed how prosocial (e.g., helpful, comforting) the emails were. Observing exclusion (vs. inclusion) activated regions associated with mentalizing (dorsomedial prefrontal cortex, medial prefrontal cortex, precuneus), and highly empathic individuals activated both mentalizing regions and social pain-related regions (anterior insula, dorsal anterior cingulate cortex). Additionally, the empathy-related activity in the anterior insula and medial prefrontal cortex was associated with later prosocial behavior toward the victim, and exploratory mediation analyses indicated that medial prefrontal cortex activity, in particular, may support the link between trait empathy and prosocial behavior. Overall, findings suggest that empathy-related neural responses to social experiences may promote spontaneous prosocial treatment of those in need.
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The Wolfpack Effect: Perception of Animacy Irresistibly Influences Interactive Behavior
Tao Gao, Gregory McCarthy & Brian Scholl
Psychological Science, December 2010, Pages 1845-1853
Abstract:
Imagine a pack of predators stalking their prey. The predators may not always move directly toward their target (e.g., when circling around it), but they may be consistently facing toward it. The human visual system appears to be extremely sensitive to such situations, even in displays involving simple shapes. We demonstrate this by introducing the wolfpack effect, which is found when several randomly moving, oriented shapes (darts, or discs with "eyes") consistently point toward a moving disc. Despite the randomness of the shapes' movement, they seem to interact with the disc - as if they are collectively pursuing it. This impairs performance in interactive tasks (including detection of actual pursuit), and observers selectively avoid such shapes when moving a disc through the display themselves. These and other results reveal that the wolfpack effect is a novel "social" cue to perceived animacy. And, whereas previous work has focused on the causes of perceived animacy, these results demonstrate its effects, showing how it irresistibly and implicitly shapes visual performance and interactive behavior.
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The evolution of punishment through reputation
Miguel dos Santos, Daniel Rankin & Claus Wedekind
Proceedings of the Royal Society: Biological Sciences, 7 February 2011, Pages 371-377
Abstract:
Punishment of non-cooperators has been observed to promote cooperation. Such punishment is an evolutionary puzzle because it is costly to the punisher while beneficial to others, for example, through increased social cohesion. Recent studies have concluded that punishing strategies usually pay less than some non-punishing strategies. These findings suggest that punishment could not have directly evolved to promote cooperation. However, while it is well established that reputation plays a key role in human cooperation, the simple threat from a reputation of being a punisher may not have been sufficiently explored yet in order to explain the evolution of costly punishment. Here, we first show analytically that punishment can lead to long-term benefits if it influences one's reputation and thereby makes the punisher more likely to receive help in future interactions. Then, in computer simulations, we incorporate up to 40 more complex strategies that use different kinds of reputations (e.g. from generous actions), or strategies that not only include punitive behaviours directed towards defectors but also towards cooperators for example. Our findings demonstrate that punishment can directly evolve through a simple reputation system. We conclude that reputation is crucial for the evolution of punishment by making a punisher more likely to receive help in future interactions, and that experiments investigating the beneficial effects of punishment in humans should include reputation as an explicit feature.
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Nora Walter, Sebastian Markett, Christian Montag & Martin Reuter
Social Neuroscience, forthcoming
Abstract:
Social loafing and social facilitation are stable behavioral effects that describe increased or decreased motivation, as well as effort and cooperation in teamwork as opposed to individual working situations. Recent twin studies demonstrate the heritability of cooperative behavior. Brain imaging studies have shown that reciprocity, cooperativeness, and social rewards activate reward processing areas with strong dopaminergic input, such as the ventral striatum. Thus, candidate genes for social behavior are hypothesized to affect dopaminergic neurotransmission. In the present study, we investigated the dopaminergic genetic contribution to social cooperation, especially to social loafing and social facilitation. N = 106 healthy, Caucasian subjects participated in the study and were genotyped for three polymorphisms relevant to the dopaminergic system (COMTval158met, DRD2 c957t, DRD2 rs#2283265). In addition to a main effect indicating an increased performance in teamwork situations, we found a significant interaction between a haplotype block covering both DRD2 single nucleotide polymorphisms (SNPs) (rs#6277 and rs#2283265), henceforth referred to as the DRD2-haplotype block, and the COMT val158met polymorphism (rs#4680) with social facilitation. Carriers of the DRD2 CT-haplotype block and at least one Val-allele showed a greater increase in performance in teamwork settings when compared with carriers of the CT-haplotype block and the Met/Met-genotype. Our results suggest that epistasis between COMTval158met and the two DRD2 SNPs contributes to individual differences in cooperativeness in teamwork settings.
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Molecular and regulatory properties of a public good shape the evolution of cooperation
Rolf Kümmerli & Sam Brown
Proceedings of the National Academy of Sciences, 2 November 2010, Pages 18921-18926
Abstract:
Public goods cooperation abounds in nature, occurring in organisms ranging from bacteria to humans. Although previous research focused on the behavioral and ecological conditions favoring cooperation, the question of whether the molecular and regulatory properties of the public good itself can influence selection for cooperation has received little attention. Using a metapopulation model, we show that extended molecular durability of a public good - allowing multiple reuse across generations - greatly reduces selection for cheating if (and only if) the production of the public good is facultatively regulated. To test the apparent synergy between public goods durability and facultative regulation, we examined the production of iron-scavenging pyoverdin molecules by the bacterium Pseudomonas aeruginosa, a cooperative behavior that is facultatively regulated in response to iron availability. We show that pyoverdin is a very durable public good and that extended durability significantly enhances fitness. Consistent with our model, we found that nonsiderophore-producing mutants (cheats) had a relative fitness advantage over siderophore producers (cooperators) when pyoverdin durability was low but not when durability was high. This was because cooperators facultatively reduced their investment in pyoverdin production when enough pyoverdin had accumulated in the media - a cost-saving strategy that minimized the ability of cheats to invade. These findings show how molecular properties of cooperative acts can shape the costs and benefits of cooperation.
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Looking on the Bright Side of Serotonin Transporter Gene Variation
Judith Homberg & Klaus-Peter Lesch
Biological Psychiatry, forthcoming
Abstract:
Converging evidence indicates an association of the short (s), low-expressing variant of the repeat length polymorphism, serotonin transporter-linked polymorphic region (5-HTTLPR), in the human serotonin transporter gene (5-HTT, SERT, SLC6A4) with anxiety-related traits and increased risk for depression in interaction with psychosocial adversity across the life span. However, genetically driven deficient serotonin transporter (5-HTT) function would not have been maintained throughout evolution if it only exerted negative effects without conveying any gain of function. Here, we review recent findings that humans and nonhuman primates carrying the s variant of the 5-HTTLPR outperform subjects carrying the long allele in an array of cognitive tasks and show increased social conformity. In addition, studies in 5-HTT knockout rodents are included that provide complementary insights in the beneficial effects of the 5-HTTLPR s-allele. We postulate that hypervigilance, mediated by hyperactivity in corticolimbic structures, may be the common denominator in the anxiety-related traits and (social) cognitive superiority of s-allele carriers and that environmental conditions determine whether a response will turn out to be negative (emotional) or positive (cognitive, in conformity with the social group). Taken together, these findings urge for a conceptual change in the current deficit-oriented connotation of the 5-HTTLPR variants. In fact, these factors may counterbalance or completely offset the negative consequences of the anxiety-related traits. This notion may not only explain the modest effect size of the 5-HTTLPR and inconsistent reports but may also lead to a more refined appreciation of allelic variation in 5-HTT function.
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Griet Emonds et al.
Journal of Neuroscience, Psychology, and Economics, forthcoming
Abstract:
Using functional MRI, we investigate the neural correlates of intrinsic versus extrinsic motivation to cooperate by comparing people who differ in the personality trait Social Value Orientation. Participants (n = 28) played several one-shot prisoner's dilemma games (offering weak cooperative incentives) and coordination games (offering strong cooperative incentives) with anonymous partners while they were under the scanner. Behavioral results indicate that proself individuals adjust their behavior toward more cooperation when extrinsic incentives were present, while prosocials' decisions are not affected by game context. The neurological data is consistent with a priori developed hypotheses regarding different behavioral strategies, and suggest that extrinsically motivated proself strategies are driven by calculation and a situation-by-situation approach. Increased activation was found in dorsolateral prefrontal cortex, posterior superior temporal sulcus (STS), and precuneus. Intrinsically motivated prosocials' strategies reflect norm compliance, routine moral judgment, and social awareness. Increased activation was found in lateral orbitofrontal cortex, anterior STS, and inferior parietal lobule.
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Playing prosocial video games increases empathy and decreases schadenfreude
Tobias Greitemeyer, Silvia Osswald & Markus Brauer
Emotion, December 2010, Pages 796-802
Abstract:
Past research provided abundant evidence that exposure to violent video games increases aggressive tendencies and decreases prosocial tendencies. In contrast, research on the effects of exposure to prosocial video games has been relatively sparse. The present research found support for the hypothesis that exposure to prosocial video games is positively related to prosocial affect and negatively related to antisocial affect. More specifically, two studies revealed that playing a prosocial (relative to a neutral) video game increased interpersonal empathy and decreased reported pleasure at another's misfortune (i.e., schadenfreude). These results lend further credence to the predictive validity of the General Learning Model (Buckley & Anderson, 2006) for the effects of media exposure on social tendencies.
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The evolution of payoff matrices: Providing incentives to cooperate
Erol Akçay & Joan Roughgarden
Proceedings of the Royal Society: Biological Sciences, forthcoming
Abstract:
Most of the work in evolutionary game theory starts with a model of a social situation that gives rise to a particular payoff matrix and analyses how behaviour evolves through natural selection. Here, we invert this approach and ask, given a model of how individuals behave, how the payoff matrix will evolve through natural selection. In particular, we ask whether a prisoner's dilemma game is stable against invasions by mutant genotypes that alter the payoffs. To answer this question, we develop a two-tiered framework with goal-oriented dynamics at the behavioural time scale and a diploid population genetic model at the evolutionary time scale. Our results are two-fold: first, we show that the prisoner's dilemma is subject to invasions by mutants that provide incentives for cooperation to their partners, and that the resulting game is a coordination game similar to the hawk-dove game. Second, we find that for a large class of mutants and symmetric games, a stable genetic polymorphism will exist in the locus determining the payoff matrix, resulting in a complex pattern of behavioural diversity in the population. Our results highlight the importance of considering the evolution of payoff matrices to understand the evolution of animal social systems.