Inequality and visibility of wealth in experimental social networks

How digital inclusive finance promotes social entrepreneurship: Evidence from 282 cities in China

Social entrepreneurship (SE) plays a positive role in addressing a range of social issues, and thus it is essential to study how to promote SE. Using panel data from 282 Chinese cities from 2011 to 2021, this study explores the mechanism through which digital inclusive finance affects SE. The results indicate that digital inclusive finance has a positive impact on SE, which still holds after considering endogeneity and undergoing a series of robustness tests. In addition, mechanism analysis shows that digital inclusive finance affects SE by alleviating financing constraints and promoting common prosperity. Furthermore, the effect of digital inclusive finance is stronger in cities with a strong Buddhist culture and more judicially civilized. Policy recommendations are also proposed.

Blocking of counter-partisan accounts drives political assortment on Twitter

There is strong political assortment of Americans on social media networks. This is typically attributed to preferential tie formation (i.e. homophily) among those with shared partisanship. Here, we demonstrate an additional factor beyond homophily driving assorted networks: preferential prevention of social ties. In two field experiments on Twitter, we created human-looking bot accounts that identified as Democrats or Republicans, and then randomly assigned users to be followed by one of these accounts. In addition to preferentially following-back copartisans, we found that users were 12 times more likely to block counter-partisan accounts compared to copartisan accounts in the first experiment, and 4 times more likely to block counter-partisan accounts relative to a neutral account or a copartisan account in the second experiment. We then replicated these findings in a survey experiment and found evidence of a key motivation for blocking: wanting to avoid seeing any content posted by the blocked user. Additionally, we found that Democrats preferentially blocked counter-partisans more than Republicans, and that this asymmetry was likely due to blocking accounts who post low-quality or politically slanted content (rather than an asymmetry in identity-based blocking). Our results demonstrate that preferential blocking of counter-partisans is an important phenomenon driving political assortment on social media.

How does economic inequality shape conspiracy theories? Empirical evidence from China

Conspiracy theories tend to be prevalent, particularly in societies with high economic inequality. However, few studies have examined the relationship between economic inequality and belief in conspiracy theories. We propose that economic inequality leads people to believe conspiracy theories about economically advantaged groups (i.e., upwards conspiracy theories) and that moral evaluations of those groups mediate this relationship. Study 1 (N = 300) found support for these ideas in a survey among Chinese residents. Study 2 (N = 160) manipulated participants' perceptions of economic inequality in a virtual society. The manipulation shaped moral evaluations of economically advantaged groups, and conspiracy beliefs, in the predicted manner. In Study 3 (N = 191) and Study 4 (N = 210), we experimentally manipulated participants' perceptions of economic inequality in real Chinese society and replicated the results of Study 2. In addition, in Study 4, we find that economic inequality predicts belief in conspiracy theories about economically disadvantaged groups (i.e., downward conspiracy theories), which was mediated by anomie. We conclude that perceived economic inequality predicts conspiracy theories about economically advantaged groups and that moral evaluations account for this effect. Also, upward and downward conspiracy theory beliefs are associated with different psychological processes.

Efficiency and resilience of cooperation in asymmetric social dilemmas

Direct reciprocity is a powerful mechanism for cooperation in social dilemmas. The very logic of reciprocity, however, seems to require that individuals are symmetric, and that everyone has the same means to influence each others' payoffs. Yet in many applications, individuals are asymmetric. Herein, we study the effect of asymmetry in linear public good games. Individuals may differ in their endowments (their ability to contribute to a public good) and in their productivities (how effective their contributions are). Given the individuals' productivities, we ask which allocation of endowments is optimal for cooperation. To this end, we consider two notions of optimality. The first notion focuses on the resilience of cooperation. The respective endowment distribution ensures that full cooperation is feasible even under the most adverse conditions. The second notion focuses on efficiency. The corresponding endowment distribution maximizes group welfare. Using analytical methods, we fully characterize these two endowment distributions. This analysis reveals that both optimality notions favor some endowment inequality: More productive players ought to get higher endowments. Yet the two notions disagree on how unequal endowments are supposed to be. A focus on resilience results in less inequality. With additional simulations, we show that the optimal endowment allocation needs to account for both the resilience and the efficiency of cooperation.

Measuring Subjective Inequality: Development and Validation of the Perceived Economic Inequality Scale (PEIS)

The main goal of the present research is to develop and validate the Perceived Economic Inequality Scale (PEIS), an instrument measuring individuals' perceptions of economic inequality at the national level. The study was conducted on a representative sample of the Italian population (N = 1,446, 51% women). The factorial structure of the scale was assessed through cross-validated exploratory-confirmatory factor analyses. To inspect the PEIS psychometric properties, item and correlation analyses were performed. The results showed that the PEIS is a valid and reliable unidimensional measure of perceived economic inequality at the national level. Further support of the PEIS construct validity was provided by the correlation of the scale score with the perceived wage gap and ideological beliefs like the economic system justification, social dominance orientation, meritocratic beliefs, and participants' political orientation. Crucially, multigroup confirmatory factor analysis supported configural, metric, and scalar invariances of the scale across socio-demographic groups. The PEIS allows researchers to assess the subjective component of economic inequality by also serving as a useful tool for unpacking the psychological correlates of perceived inequality.

Subjective economic inequality is associated with lower well-being through more upward comparison and lower trust

Individuals often misconstrue the actual degree of economic inequality, which might account for the ambiguity in the literature about the role that inequality plays in well-being. Instead of focusing on objective inequality, we propose a subjective inequality approach by investigating the long-term association between subjective economic inequality and well-being (N = 613). We found that subjective inequality predicted lower life satisfaction and higher depression one year later, which were accounted for by more upward socioeconomic comparison and lower trust. Furthermore, the negative association between subjective inequality and well-being remained constant, regardless of individuals' objective socioeconomic status (SES), subjective SES, and mindset of SES. The long-term association between subjective inequality and well-being remained robust after controlling for prior levels of well-being and multiple covariates. Our findings revealed that subjective inequality is detrimental to well-being and opens a new window into psychological research on economic inequality.

Complex pathways to cooperation emergent from asymmetry in heterogeneous populations

Cooperation within asymmetric populations has garnered significant attention in evolutionary games. This paper explores cooperation evolution in populations with weak and strong players, using a game model where players choose between cooperation and defection. Asymmetry stems from different benefits for strong and weak cooperators, with their benefit ratio indicating the degree of asymmetry. Varied rankings of parameters including the asymmetry degree, cooperation costs, and benefits brought by weak players give rise to scenarios including the prisoner's dilemma (PDG) for both player types, the snowdrift game (SDG), and mixed PDG-SDG interactions. Our results indicate that in an infinite well-mixed population, defection remains the dominant strategy when strong players engage in the prisoner's dilemma game. However, if strong players play snowdrift games, global cooperation increases with the proportion of strong players. In this scenario, strong cooperators can prevail over strong defectors when the proportion of strong players is low, but the prevalence of cooperation among strong players decreases as their proportion increases. In contrast, within a square lattice, the optimum global cooperation emerges at intermediate proportions of strong players with moderate degrees of asymmetry. Additionally, weak players protect cooperative clusters from exploitation by strong defectors. This study highlights the complex dynamics of cooperation in asymmetric interactions, contributing to the theory of cooperation in asymmetric games.

The psychological imprint of inequality: Economic inequality shapes achievement and power values in human life

OBJECTIVE

This research investigates how economic inequality shapes basic human values across three cross-national, cross-regional, and longitudinal studies (Ntotal  = 219,697).

METHODS

Study 1 examined the relationship between objective economic inequality and values across 77 societies from all five continents (n = 170,525). Study 2 examined the relationship between objective economic inequality and values across 51 regions in the United States (n = 48,559). Study 3 used a two-year longitudinal design to examine the relationship between perceived economic inequality and values (n = 613).

RESULTS

Results from multilevel modeling and longitudinal analysis suggested that people who lived in areas with higher economic inequality and who perceived higher economic inequality were more likely to endorse achievement and power values. Moreover, people who perceived higher economic inequality were less likely to endorse benevolence values. These effects were robust in within-country tests (Studies 2 and 3) but not in the cross-country tests (Study 1) when accounting for sociodemographic characteristics.

CONCLUSIONS

Our findings suggest that economic inequality may act as an antecedent of self-enhancement values, particularly within countries. In a world of rising economic inequality, this may over time lead to an overemphasis on achievement and power which have been shown to erode social cohesion.

Longitudinal Changes in Chinese Prosociality

This article presents three studies using data from the World Values Survey, 128 published studies, and China Family Panel Studies to comprehensively examine the longitudinal dynamics of Chinese prosociality, encompassing prosocial attitudes, tendencies, and behaviors, with the overarching goal of shedding light on the evolving nature of prosociality in the Chinese context. These studies reveal a consistent pattern, illustrating a decline followed by a resurgence in all three aspects, with a nadir around 2014. In addition, the study investigates the intricate relationship between economic inequality, prosocial behavior, and prosocial attitudes. The findings suggest that while economic inequality significantly relates to prosocial behavior, it does not entirely explain its fluctuations. Prosocial attitudes partially mediate the connection between economic inequality and prosocial behavior. These insights suggest that addressing inequality could contribute to a more conducive social environment for societal-level prosociality. However, further research is imperative to explore additional determinants of prosociality shifts.

Emergence and collapse of reciprocity in semiautomatic driving coordination experiments with humans

Forms of both simple and complex machine intelligence are increasingly acting within human groups in order to affect collective outcomes. Considering the nature of collective action problems, however, such involvement could paradoxically and unintentionally suppress existing beneficial social norms in humans, such as those involving cooperation. Here, we test theoretical predictions about such an effect using a unique cyber-physical lab experiment where online participants (N = 300 in 150 dyads) drive robotic vehicles remotely in a coordination game. We show that autobraking assistance increases human altruism, such as giving way to others, and that communication helps people to make mutual concessions. On the other hand, autosteering assistance completely inhibits the emergence of reciprocity between people in favor of self-interest maximization. The negative social repercussions persist even after the assistance system is deactivated. Furthermore, adding communication capabilities does not relieve this inhibition of reciprocity because people rarely communicate in the presence of autosteering assistance. Our findings suggest that active safety assistance (a form of simple AI support) can alter the dynamics of social coordination between people, including by affecting the trade-off between individual safety and social reciprocity. The difference between autobraking and autosteering assistance appears to relate to whether the assistive technology supports or replaces human agency in social coordination dilemmas. Humans have developed norms of reciprocity to address collective challenges, but such tacit understandings could break down in situations where machine intelligence is involved in human decision-making without having any normative commitments.

Effect of economic inequality on generosity: A social norm perspective

Economic inequality has been found to reduce individuals' generosity in western contexts. However, whether this effect is cross-culturally consistent and its internal mechanism remain unclear, as well as how to mitigate this impact. Hence, we explored whether and why economic inequality may erode generosity in a sample of Chinese adults from the social norm perspective and introduced the equal allocation norm to mitigate this effect. Four online studies were conducted: two were correlational (Study 1: n = 300; Study 2: n = 568) and two were experimental (Study 3: n = 289; Study 4: n = 500). Results showed that economic inequality predicted less generosity in the dictator game, and perceived unequal allocation norm accounted for this effect. Moreover, introducing the equal allocation norm could buffer this negative effect. Findings suggest economic inequality impairs generosity, and making the equal allocation norm more salient may guide people to act more generously.

Reputations for treatment of outgroup members can prevent the emergence of political segregation in cooperative networks

Reputation systems promote cooperation and tie formation in social networks. But how reputations affect cooperation and the evolution of networks is less clear when societies are characterized by fundamental, identity-based, social divisions like those centered on politics in the contemporary U.S. Using a large web-based experiment with participants (N = 1073) embedded in networks where each tie represents the opportunity to play a dyadic iterated prisoners' dilemma, we investigate how cooperation and network segregation varies with whether and how reputation systems track behavior toward members of the opposing political party (outgroup members). As predicted, when participants know others' political affiliation, early cooperation patterns show ingroup favoritism. As a result, networks become segregated based on politics. However, such ingroup favoritism and network-level political segregation is reduced in conditions in which participants know how others behave towards participants from both their own party and participants from the other party. These findings have implications for our understanding of reputation systems in polarized contexts.

Partner choice and cooperation in social dilemmas can increase resource inequality

Cooperation is more likely when individuals can choose their interaction partner. However, partner choice may be detrimental in unequal societies, in which individuals differ in available resources and productivity, and thus in their attractiveness as interaction partners. Here we experimentally examine this conjecture in a repeated public goods game. Individuals (n = 336), participating in groups of eight participants, are assigned a high or low endowment and a high or low productivity factor (the value that their cooperation generates), creating four unique participant types. On each round, individuals are either assigned a partner (assigned partner condition) or paired based on their self-indicated preference for a partner type (partner choice condition). Results show that under partner choice, individuals who were assigned a high endowment and high productivity almost exclusively interact with each other, forcing other individuals into less valuable pairs. Consequently, pre-existing resource differences between individuals increase. These findings show how partner choice in social dilemmas can amplify resource inequality.

Economic inequality increases the number of hours worked and decreases work-life balance perceptions: longitudinal and experimental evidence

International institutions' attention to work-life balance (WLB) demonstrates the global breadth of this issue. Yet the scientific community has thus far paid little attention to its structural underpinnings and to the interplay between these macro-level underpinnings and individual psychological factors. We examine the contextual role of economic inequality at the national level as a significant factor influencing working time and WLB perceptions using multiple empirical strategies. In the first set of studies (1a and 1b), we compared countries with different levels of inequality (Study 1a with 37 countries, Study 1b with longitudinal data from 34 countries, N = 254) and found increased working time and reduced WLB in highly unequal countries. In a pilot study (N = 81) and in the pre-registered Studies 2 (N = 338) and 3 (N = 499) we corroborated this evidence with an experimentally induced inequality perception, reporting an indirect effect of inequality on WLB (Studies 2 and 3) and working time (Study 3) through status anxiety and competitiveness. In Study 2, we manipulated socio-economic class in addition to economic inequality, showing that the detrimental effect of inequality on WLB is especially marked for participants assigned to a low-class condition. This research contributes to an integrated understanding of the impact of economic inequality and socio-economic class in shaping WLB and provides useful insights for organizations to develop context-specific policies to improve employees' WLB that take both individual and structural factors into account.

On the lowest rung of the ladder: How social exclusion, perceived economic inequality and stigma increase homeless people's resignation

Despite the relevance of social exclusion and economic inequality for homelessness, empirical studies investigating how these issues relate to homeless people's psychological well-being are scarce. We aimed to fill this gap by conducting two quasi-experimental studies on homeless and non-homeless groups. The first study (N = 200) showed that homeless (vs. non-homeless) people presented higher levels of resignation, characterized by depression, alienation, helplessness, and unworthiness (Williams, 2009). The second study (N = 183) replicated the findings from Study 1 and showed that perceived economic inequality could increase homeless people's resignation by emphasizing perceptions of social exclusion. Additional analyses found that identification with the stigmatized homeless group could mediate the relationship between perceived inequality and social exclusion, increasing the resignation. Overall, the results showed that chronic social exclusion of homeless people is associated with higher levels of resignation. Moreover, they showed the role of perceived economic inequality and homeless group stigmatized identification as group-specific mechanisms favouring social exclusion and ultimately worsening psychological well-being.

The interdependence of relational and material wealth inequality in Pemba, Zanzibar

The extent of inequality in material wealth across different types of societies is well established. Less clear, however, is how material wealth is associated with relational wealth, and the implications of such associations for material wealth inequality. Theory and evidence suggest that material wealth both guides, and is patterned by, relational wealth. While existing comparative studies typically assume complementarity between different types of wealth, such associations may differ for distinct kinds of relational wealth. Here, we first review the literature to identify how and why different forms of relational wealth may align. We then turn to an analysis of household-level social networks (food sharing, gender-specific friendship and gender-specific co-working networks) and material wealth data from a rural community in Pemba, Zanzibar. We find that (i) the materially wealthy have most relational ties, (ii) the associations between relational and material wealth-as well as relational wealth more generally-are patterned by gender differences, and (iii) different forms of relational wealth have similar structural properties and are closely aligned. More broadly, we show how examining the patterning of distinct types of relational wealth provides insights into how and why inequality in material wealth remains muted in a community undergoing rapid economic change. This article is part of the theme issue 'Evolutionary ecology of inequality'.

Data repurposing from digital home cage monitoring enlightens new perspectives on mouse motor behaviour and reduction principle

In this longitudinal study we compare between and within-strain variation in the home-cage spatial preference of three widely used and commercially available mice strains-C57BL/6NCrl, BALB/cAnNCrl and CRL:CD1(ICR)-starting from the first hour post cage-change until the next cage-change, for three consecutive intervals, to further profile the circadian home-cage behavioural phenotypes. Cage-change can be a stressful moment in the life of laboratory mice, since animals are disturbed during the sleeping hours and must then rapidly re-adapt to a pristine environment, leading to disruptions in normal motor patterns. The novelty of this study resides in characterizing new strain-specific biological phenomena, such as activity along the cage walls and frontality, using the vast data reserves generated by previous experimental data, thus introducing the potential and exploring the applicability of data repurposing to enhance Reduction principle when running in vivo studies. Our results, entirely obtained without the use of new animals, demonstrate that also when referring to space preference within the cage, C57BL/6NCrl has a high variability in the behavioural phenotypes from pre-puberty until early adulthood compared to BALB/cAnNCrl, which is confirmed to be socially disaggregated, and CRL:CD1(ICR) which is conversely highly active and socially aggregated. Our data also suggest that a strain-oriented approach is needed when defining frequency of cage-change as well as maximum allowed animal density, which should be revised, ideally under the EU regulatory framework as well, according to the physiological peculiarities of the strains, and always avoiding the "one size fits all" approach.

Higher income individuals are more generous when local economic inequality is high

There is ongoing debate about whether the relationship between income and pro-social behaviour depends on economic inequality. Studies investigating this question differ in their conclusions but are consistent in measuring inequality at aggregated geographic levels (i.e. at the state, region, or country-level). I hypothesise that local, more immediate manifestations of inequality are important for driving pro-social behaviour, and test the interaction between income and inequality at a much finer geographical resolution than previous studies. I first analyse the charitable giving of US households using ZIP-code level measures of inequality and data on tax deductible charitable donations reported to the IRS. I then examine whether the results generalise using a large-scale UK household survey and neighbourhood-level inequality measures. In both samples I find robust evidence of a significant interaction effect, albeit in the opposite direction as that which has been previously postulated-higher income individuals behave more pro-socially rather than less when local inequality is high.

Wage (in)equality matters: the effect of organizational economic inequality on others' and self-ascriptions

Economic inequality has consequences at the social-psychological level, such as in the way people make inferences about their environment and other people. In the present two preregistered studies, we used a paradigm of an organizational setting to manipulate economic inequality and measured ascriptions of agentic versus communal traits to employees and the self. In Study 1 (N = 187), participants attributed more agency than communion to a middle-status employee, and more communion than agency when economic equality was salient. In Study 2 (N = 198) this finding was replicated. Further, this inequality-agency association was explained by perceptions of competitive employee relationships. Results, moreover, suggested that participants mainly attributed more communion than agency to themselves in the equality condition. We conclude that agency and communion ascriptions may be functional and thus inform about the expectations people have on the nature of social relationships in the face of economic inequality.

The Gap Between Us: Income Inequality Reduces Social Affiliation in Dyadic Interactions

In this investigation, we tested the hypothesis that increased income inequality between individuals will reduce social affiliation within dyadic interactions. In three experiments, we examined the effects of income inequality on key indices of affiliation using semi-structured interactions. In the first two experiments, a participant and confederate were randomly assigned to a low- or high-power role and compensated mildly or extremely unequally. In Experiment 3, inequality and inequity were orthogonally manipulated to determine whether inequality's social consequences are moderated by the fairness of the income distribution. We demonstrated that greater inequality produced more negative emotional responses, reduced desire for closeness, and harsher evaluations of one's partner, regardless of one's power role and the equitability of the income distribution. We also obtained evidence that greater inequality reduces behavioral warmth, although this effect was less consistent. Our results begin to unpack the psychological processes through which income inequality worsens societal well-being.

Promoting prosocial behavior in an unequal world

Amid a global pandemic and the climate crisis, there is an increasing need to understand how to promote largescale, coordinated action between different groups. Yet certain factors such as inequality can hinder cooperation. We aimed to establish how to orient groups toward a superordinate goal when they have unequal resources. Participants were divided into two 'countries' and asked to assemble LEGO bricks into food (by building pieces in a certain order) to prevent starvation among 'the people'. One 'country' had few LEGO bricks whereas the other had an abundance, and the only way to maximize food creation was for the groups to work together. We assessed the efficacy of three diverse interventions on superordinate behavior and attitudes: compassion meditation training (Study 1), lower inequality (Study 2), and the introduction of a pro-sharing group norm by a confederate (Study 3). Compassion meditation training and altering the degree of inequality between groups did not have a clear effect on collaborative action. Only the introduction of a pro-sharing group norm enhanced sharing behavior, made participants feel more cooperative and reduced fears of being compassionate toward others. Our findings speak to the importance of leadership in promoting coordinated action to address challenges that face the superordinate group.

Resource asymmetry reduces generosity and paying forward generosity, among the resource-advantaged and disadvantaged

Decisions to benefit others often entail generalized reciprocity: helping someone who cannot directly return benefits in the future; instead, the beneficiary may "pay it forward" to someone else. While much past work demonstrates that people pay forward generosity, experimental tests of these processes typically assume that people have equal access to same-valued resources that they can use to benefit others. Yet this is rare in daily life, where people commonly experience asymmetries in the resources that they have to help others and to pay forward help received. In an experiment, we find that acts of generalized reciprocity-including initiating generosity and, upon being treated generously, paying it forward-are reduced when there is resource asymmetry between potential benefactors. Results show that the detriments of resource asymmetry occur among both the resource-advantaged and the disadvantaged. Asymmetry in available resources, and inequality more broadly, is thus critical for understanding patterns of generosity.

Economic inequality breeds corrupt behaviour

Economists and political scientists have long debated the relations between economic inequality and corruption at the societal level. Extending this literature, we proposed and tested that economic inequality breeds the corrupt behaviour of individuals. Analyses of 45-year archival data from the United States found that official corruption crimes were more prevalent in years and states with greater economic inequality. Three subsequent experiments (N = 776) using economic games showed that individuals exposed to greater economic inequality exhibited more corrupt behaviour in both Chinese and American cultures. Furthermore, the increased desire for wealth and the perception of reduced fairness accounted for this effect. These findings highlight that excessive economic inequality creates a competitive environment in which people give priority to themselves over others and suggest a vicious cycle between economic inequality and corruption.

Inequality and fairness with heterogeneous endowments

People differ in intelligence, cognitive ability, personality traits, motivation, and similar valued and, to a large degree, inherited characteristics that determine success and achievements. When does individual heterogeneity lead to a fair distribution of rewards and outcomes? Here, we develop this question theoretically and then test it experimentally for a set of structural conditions in a specific interaction situation. We first catalogue the functional relationship between individual endowments and outcomes to distinguish between fairness concepts such as meritocracy, equality of opportunity, equality of outcomes, and Rawl's theory of justice. We then use an online experiment to study which of these fairness patterns emerge when differently endowed individuals can share their resources with others, depending on whether information about others' endowments and outcomes is available. We find that while visible outcomes lessen inequality by decreasing the statistical dispersion of outcomes across the group, endowments need to be visible for better equality of opportunity for the most disadvantaged.

Optimized water allocation in persistent severe climatic conditions: A novel metaheuristic approach

With increasing global water tensions, the need for a comprehensive water management framework in persistent harsh conditions is crucial. A framework was designed to devise a comprehensive and detailed plan that can strike a balance between all water resources and demands. In contrast to previous studies, this framework can be adopted for long-lasting severe climatic conditions and suggests detailed cultivation patterns and reservoir management. The framework adopts a comprehensive, detailed, novel, multi-objective, and evolutionary-based approach for optimal water management during continuous extreme events in sectors including agriculture, industry, and the environment. Sustainability (ecological water demand and global warming potential), economic welfare, and equitability are allocation principles. This framework utilizes complex, metaheuristic algorithms that enable it to cope with big data and optimize complex systems with high precision. For the case study of the Karkheh basin, the results show that for a full recovery of the Hoor al-Azim wetland, the basin cannot bear the agricultural water demand, and such activities must be decreased drastically. It is also shown that a 10% increase of the agricultural net benefit will result in a 40% increase of the Gini coefficient.

The influence of signs of social class on compassionate responses to people in need

A field experiment (N = 4,536) examined how signs of social class influence compassionate responses to those in need. Pedestrians in two major cities in the United States were exposed to a confederate wearing symbols of relatively high or low social class who was requesting money to help the homeless. Compassionate responding was assessed by measuring the donation amount of the pedestrians walking past the target. Pedestrians gave more than twice (2.55 times) as much money to the confederate wearing higher-class symbols than they did to the one wearing lower-class symbols. A follow-up study (N = 504) exposed participants to images of the target wearing the same higher- or lower-class symbols and examined the antecedents of compassionate responding. Consistent with theorizing, higher-class symbols elicited perceptions of elevated competence, trustworthiness, similarity to the self, and perceived humanity compared to lower-class symbols. These results indicate that visible signs of social class influence judgments of others’ traits and attributes, as well as in decisions to respond compassionately to the needs of those who are suffering.

Inequality in abundance

With technological advance has come the possibility of a new era of abundance. Technologies like 3D printing and robotics promise to lower the costs of production and distribution of goods and services, presumably making these goods and services readily available to those across income and wealth spectrums. This undoubtedly is a good thing. But what will be the effect of these technologies on existing wealth inequalities and the psychological and societal burdens they impose? Can we expect that this newfound abundance will help remedy the current historic levels of inequality in the U.S. and other western countries? Unfortunately, the answer is likely no, for two reasons. First, history suggests that inequality often persists even under conditions of abundance due to dynamics of power and politics and ongoing impacts of structural inequalities. Having more than enough of a particular good or service to go around does not guarantee that all will have access to this good or service. Second, even if the new abundance enabled by technology extends into all levels of the socioeconomic spectrum, enabling individuals to access goods and services (and their attendant benefits) previously beyond their reach, the harms that attend unequal societies will persist. Increasing evidence suggests that these harms, including increased violence and decreased health, arise not from access (or a lack thereof) to particular goods and services, but from the adverse psychological consequences of living in an unequal society. This is a psychological burden shared not just by those at the losing end of the inequality equation, but also those who enjoy a relative advantage in society. Unequal societies are psychologically harmful to all who live in them, regardless of where these individuals fall on the socioeconomic spectrum, and largely independent of the particular goods and services they enjoy. The upshot is that society cannot rely on new abundance technologies to automatically solve problems of inequality and the social and psychological burdens that plague those who live in unequal societies. Indeed, depending on how society responds to questions of access to these technologies, their introduction might exacerbate various forms of inequality. In light of this, it is crucial to address conditions of inequality head-on, so that the new era of abundance promised by technological advance can lead to real gains in individual and societal wellbeing.

The links among relative financial scarcity, thinking style, fatalism, and well-being

In the present research, we examined the links among relative financial scarcity, thinking style, fatalism, and well-being and their roles in predicting protective behaviors against COVID-19. Study 1 (N = 120) revealed that after an experimental manipulation to induce the perception of relative financial scarcity (versus financial abundance), people who perceived higher relative financial scarcity changed their thinking style to a more concrete mindset. In Study 2 (N = 873), the relative financial abundance-scarcity situation was measured, and the results showed that the greater the perceived relative financial scarcity was, the more concrete the mindset and the lower the sense of well-being. Importantly, we found that individuals who felt poorer but maintained an abstract thinking style reported higher well-being. Study 3 (N = 501) examined the influence of a concrete thinking style in people who perceived that their economic situation had worsened with the pandemic. The results showed that when this vulnerable population presented a more concrete mindset, they reported lower well-being, higher fatalism, and lower protective behavior against COVID-19. Thus, maintaining an abstract mindset promotes higher well-being, lower fatalism, and greater protective behaviors against COVID-19, even under economic difficulties. Because thinking style can be modified, our results encourage the development of new social intervention programs to promote an abstract mindset when people face important challenges.

Lower social status predicts greater behavioral trust in social exchanges

The motivated attributions model of trust development suggests that trustors ameliorate the anxiety associated with dependence by perceiving others as trustworthy and then engage in seemingly irrational acts of trust, despite these acts being extremely risky. Accordingly, I predicted that individuals with lower social status would demonstrate more trusting behavior than would higher status individuals, and that this tendency would be explained by the lower sense of power of people with a lower social status. I tested the hypotheses using both correlational and experimental designs, with samples representing people from a diverse range of social class backgrounds and controlling for plausible alternative explanations. The results have theoretical and practical implications for understanding how inequality and hierarchy mold actions.

Economic inequality shapes the agency–communion content of gender stereotypes

Economic inequality is a main issue in current societies, and it affects people’s psychological processes. In this research, we propose that perceived economic inequality might affect how people perceive men and women. In two experiments carried out in Spain ( N = 170) and Mexico ( N = 215), we tested whether high (vs. low) economic inequality leads to changes in the perceived agency and communion of both men and women. Our findings suggest that when economic inequality is high (vs. low), the communal content in social perceptions of both men and women decreases. Specifically, under high (vs. low) inequality, the difference in agency and communion ascribed to a man becomes greater (i.e., men are perceived as even more agentic than communal), whereas this difference becomes smaller for women (i.e., women are still perceived as more communal than agentic, but this difference is smaller). We discuss these findings’ implications regarding the psychosocial effects of economic inequality.

Inequality and cooperation in social networks

Social networks are fundamental to the broad scale cooperation observed in human populations. But by structuring the flow of benefits from cooperation, networks also create and sustain macro-level inequalities. Here we ask how two aspects of inequality shape the evolution of cooperation in dynamic social networks. Results from a crowdsourced experiment (N = 1080) show that inequality alters the distribution of cooperation within networks such that participants engage in more costly cooperation with their wealthier partners in order to maintain more valuable connections to them. Inequality also influences network dynamics, increasing the tendency for participants to seek wealthier partners, resulting in structural network change. These processes aggregate to alter network structures and produce greater system-level inequality. The findings thus shed critical light on how networks serve as both boon and barrier to macro-level human flourishing.

Caution, Preprint! Brief Explanations Allow Nonscientists to Differentiate Between Preprints and Peer-Reviewed Journal Articles

A growing number of psychological research findings are initially published as preprints. Preprints are not peer reviewed and thus did not undergo the established scientific quality-control process. Many researchers hence worry that these preprints reach nonscientists, such as practitioners, journalists, and policymakers, who might be unable to differentiate them from the peer-reviewed literature. Across five studies in Germany and the United States, we investigated whether this concern is warranted and whether this problem can be solved by providing nonscientists with a brief explanation of preprints and the peer-review process. Studies 1 and 2 showed that without an explanation, nonscientists perceive research findings published as preprints as equally credible as findings published as peer-reviewed articles. However, an explanation of the peer-review process reduces the credibility of preprints (Studies 3 and 4). In Study 5, we developed and tested a shortened version of this explanation, which we recommend adding to preprints. This explanation again allowed nonscientists to differentiate between preprints and the peer-reviewed literature. In sum, our research demonstrates that even a short explanation of the concept of preprints and their lack of peer review allows nonscientists who evaluate scientific findings to adjust their credibility perception accordingly. This would allow harvesting the benefits of preprints, such as faster and more accessible science communication, while reducing concerns about public overconfidence in the presented findings.

Network rewiring promotes cooperation in an aspirational learning model

We analyze a cooperative decision-making model that is based on individual aspiration levels using the framework of a public goods game in static and dynamic networks. Sensitivity to differences in payoff and dynamic aspiration levels modulates individual satisfaction and affects subsequent behavior. The collective outcome of such strategy changes depends on the efficiency with which aspiration levels are updated. Below a threshold learning efficiency, cooperators dominate despite short-term fluctuations in strategy fractions. Categorizing players based on their satisfaction level and the resulting strategy reveal periodic cycling between the different categories. We explain the distinct dynamics in the two phases in terms of differences in the dominant cyclic transitions between different categories of cooperators and defectors. Allowing even a small fraction of nodes to restructure their connections can promote cooperation across almost the entire range of values of learning efficiency. Our work reinforces the usefulness of an internal criterion for strategy updates, together with network restructuring, in ensuring the dominance of altruistic strategies over long time-scales.

Economic Inequality Increases the Preference for Status Consumption

Prior research has shown the relationship between objective economic inequality and searching for positional goods. It also investigated the relationship between social class and low income with conspicuous consumption. However, the causal relationship between economic inequality (the difference in wealth between individuals and groups living in a shared context and consumer behavior) has been less explored. Furthermore, there are also few studies looking for the psychological mechanisms that underlie these effects. The current research’s main goal is to analyze the consequences of perceived economic inequality (PEI) on conspicuous and status consumption and the possible psychological mechanisms that could explain its effects. Furthermore, the current research aims to examine whether there is a causal relationship between PEI and materialism preferences and attitudes toward indebtedness. This work includes two preregister experimental studies. In the Study 1 (n = 252), we manipulated PEI and its legitimacy through a 2 (high vs. low inequality) × 2 (Illegitimate vs. legitimate) between-participants experiment. Results showed a main effect of PEI on status consumption, status seeking, status anxiety, materialism, and attitude toward indebtedness. No interaction effect between legitimacy and inequality was found. In the Study 2 (n = 301), we manipulated the PEI through the Bimboola Paradigm. We replicated the effect of PEI on status consumption, status seeking, and materialism and found that status seeking mediated the relationship between PEI and status and conspicuous consumption. Economic inequality affects consumer behavior and favors consumption preferences for products that provide desirable symbolic values associated with status. These results could have important implications in the interpersonal and intergroup processes, including those related to consumption and purchase.

Social agent identity cells in the prefrontal cortex of interacting groups of primates

[Figure: see text].

Comprehensive Analysis of Trends in Medicare Utilization and Reimbursement in Physical Medicine & Rehabilitation: 2012 to 2017

INTRODUCTION

There is an absence of literature describing Medicare utilization by physiatrists, despite their key role in treating Medicare enrollees with qualifying disabilities and common neuromusculoskeletal conditions.

OBJECTIVE

Analyze Medicare data regarding physiatrists and their beneficiaries, services, and reimbursement, as well as trends in utilization and geographic distribution.

DESIGN AND SETTING

Retrospective analysis of publicly available Center for Medicare & Medicaid Services data for Medicare beneficiaries receiving physiatric services from 2012-2017.

MAIN OUTCOME MEASURES

After adjustment for inflation, variables assessed for changes over time included provider and beneficiary demographics, total Medicare reimbursement, and number of services provided, subsequently separated by drug and medical service metrics. Lorenz curves and Gini coefficients were computed to study reimbursement inequality. Choropleth maps were generated to assess geographic differences in physician density and reimbursement, both by state and ZIP code.

RESULTS

The number of physiatrists utilizing Medicare increased from 7230 to 7895 from 2012-2017, while the average number of unique beneficiaries per clinician remained constant (307 vs 310; P = 0.51). Beneficiaries' mean hierarchical conditions category (HCC) health risk score, normalized to 1.0 for the average beneficiary, increased significantly from 2012-2017 (1.72 vs 1.80; P < 0.01). Mean Medicare reimbursement per physiatrist decreased significantly from 2012-2017 ($131 960 vs $117 623; P < 0.001), while mean number of services remained constant (3243 vs 3077; P = 0.132). Botulinum toxin and baclofen injections were the two most reimbursed drug-related services. Gini coefficients ranged from 0.52-0.53 for 2012-2017, suggesting moderate reimbursement inequality, with the 75th percentile receiving on average 2 times the median. Both physician density and top earners were concentrated in urban and metropolitan areas.

CONCLUSIONS

Despite rising healthcare costs and increasing medical complexity of physiatrists' beneficiaries, Medicare payments have decreased over time. These trends are relevant to both providers and policy makers, particularly in light of unequal geographic distribution of physiatrists across the country. This article is protected by copyright. All rights reserved.

How economic inequality affects prosocial behavior in children across development

Research has linked economically unequal environments to lower prosocial behavior in adults. However, we know little about how inequality affects children's prosociality. Here, 4- to 9-year-old children (N = 128) played a series of games with several puppets where points were awarded. The distribution of points was characterized by either high inequality or low inequality. Children's donation behavior (i.e., the number of stickers they donated to a poor child), resource division behavior (i.e., how they divided extra points among poor and rich puppets), and fairness perceptions (i.e., how fair they perceived the game to be) were measured in response. Although the experimental manipulation of inequality did not affect children's donations, exploratory analyses revealed that higher inequality in children's home suburb was linked to lower donation rates. Furthermore, with age, children distributed points with increasing concern for poorer individuals, and negative judgments of the inequality were linked to distributing resources to poorer individuals. Here we present the first comprehensive analysis of children's prosocial reactions to high and low inequality across development.

Ethics, morality, and the psychology of climate justice

Climate change is increasingly understood as a social justice issue by academics, policymakers, and the public; however, the nature of these perceptions and their implications for cooperation and decision-making have only recently begun to receive empirical attention. We review emerging empirical work that suggests that morality and justice perceptions can serve as both a bridge and a barrier to cooperation around climate change and highlight two critical areas for future development, identifying psychological processes that promote and impede climate vulnerability and that enhance equity in the design and implementation of climate solutions. We argue that conceptualizing climate justice as a multidimensional process addressing both social and structural barriers can stimulate new psychological research and help align disparate approaches within the social sciences.