PNAS nexus最新文献

Recent declines in the health of honey bee colonies used for crop pollination pose a considerable threat to global food security. Foraging by honey bee workers represents the primary route of exposure to a plethora of toxins and pathogens known to affect bee health, but it remains unclear how foraging preferences impact colony-level patterns of stressor exposure. Resolving this knowledge gap is crucial for enhancing the health of honey bees and the agricultural systems that rely on them for pollination. To address this, we carried out a national-scale experiment encompassing 456 Canadian honey bee colonies to first characterize pollen foraging preferences in relation to major crops and then explore how foraging behavior influences patterns of stressor exposure. We used a metagenetic approach to quantify honey bee dietary breadth and found that bees display distinct foraging preferences that vary substantially relative to crop type and proximity, and the breadth of foraging interactions can be used to predict the abundance and diversity of stressors a colony is exposed to. Foraging on diverse plant communities was associated with increased exposure to pathogens, while the opposite was associated with increased exposure to xenobiotics. Our work provides the first large-scale empirical evidence that pollen foraging behavior plays an influential role in determining exposure to dichotomous stressor syndromes in honey bees.

Political disagreement is increasingly moral, rather than economic, in nature, raising the question how the fields of political economy and moral psychology relate to each other. While these disciplines were initially deeply intertwined, cross-disciplinary exchange became rare throughout the 20th century. More recently, the tide has shifted again-social scientists of different backgrounds recognized that morality and politico-economic outcomes influence each other in rich bidirectional ways. Because psychologists and economists possess distinct and complementary skill sets, part of this movement consists of productive "economic imperialism"-economists leveraging their empirical toolkit to test and substantiate theories from moral psychology at scale or in the wild. To illustrate this, I present two case studies of recent economics research on prominent ideas in moral psychology. First is the theory that morality is ultimately functional-that it evolved as a form of "psychological and biological police" to enforce cooperation, such as in economic production and exchange. Second is that the structure of morality shapes political views and polarization, including on economic issues such as taxation and redistribution. I conclude from these case studies that economists have much to gain from integrating more ideas from moral psychology, and that moral psychologists will be able to make an even more compelling case if they engage with research in economics.

Counting and certifying election results in the United States can take days and even weeks following election day. These delays are often linked to distrust in elections but does delay cause distrust? What can election officials do to counteract distrust if counting most ballots and announcing results cannot occur on election night? Using a preregistered survey experiment of nearly 10,000 Americans, this article shows that informing voters about longer-than-expected vote counting time induces a large, significant decrease in trust in the election. However, viewing a "prebunking" video in advance of being informed of the delay in results more than makes up for the delay-induced decrease in election trust. Our findings have two important implications. First, unexpected delays in calling elections induce distrust even without misinformation from third parties. Second, providing voters with information about vote counting and the legitimate reasons for delays increases trust and mitigates the distrust induced by delays.

Recent research has shown how norms shape political and economic decision-making. Much of this work assumes that a single norm influences the behavior of all people, but in fact, many situations are characterized by the existence of competing normative viewpoints. We apply a method for measuring belief in the simultaneous existence of multiple norms. Such multiplicity arises naturally when norms are associated with distinctive groups, and thus political polarization can be characterized, in part, as a product of diverging norms between groups. We thus assess the validity of our measurement technique by testing whether it can recover polarization on seven salient political issues on which US Democrats and Republicans tend to hold different views. We then compare the norms elicited by our method to the norms of Democrats and Republicans elicited in a separate sample using an established and validated-but methodologically less rich-measurement approach. Our study uncovers a wide range of co-existing views between and within political groups. Partisans understand their group's norms and hold personal views that align with them. They can also recognize the diversity and polarization in US public opinion by identifying norms specific to political parties and acknowledging the variety of views within their own parties, which may indicate internal divisions. This research underscores the importance of nuanced approaches to political norms that go beyond party lines. By acknowledging a plurality of views, we can encourage productive discussions and bridge ideological divides.

In our polarized societies, more companies are taking a stand on divisive sociopolitical issues. However, given the mixed findings from previous studies, it remains unclear whether Corporate Activism (CA) is more likely to hurt or help a company's performance and reputation, or shape the public's attitudes toward the sociopolitical issue involved. To better understand the impact of CA in polarized societies, it is valuable to study moderating factors, especially those linked to polarization. A meta-analysis of 72 scholarly works is conducted to examine the impact of CA on various outcomes (e.g. ads and social media engagement, cognitive and attitudinal reactions, public's intentions and actions, emotional reactions, social and ethical engagement, workplace, and employee perceptions) and the role of moderators (a sociopolitical issue's political leaning and controversy level, political orientation of the target audience, key demographics). The analysis reveals a positive, albeit small, effect size (0.085 [95% CI (0.0542, 0.1158)]) with the most impact on two outcomes: cognitive and attitudinal reactions, and emotional reactions. It further reveals that companies adopting liberal-leaning CAs elicit more favorable responses than those adopting conservative CAs and that liberals respond positively to CA, while conservatives are more neutral. However, when there is alignment between the CA's political leaning and the audience's political orientation, conservatives have a stronger positive response than liberals. Also, younger audiences view CA more positively. Finally, per national culture, while power distance and individualism positively moderate the reaction to CA, uncertainty avoidance has a negative effect.

Political segregation is a pressing issue, particularly on social media platforms. Recent research suggests that one driver of segregation is political acrophily-people's preference for others in their political group who have more extreme (rather than more moderate) political views. However, acrophily has been found in lab experiments, where people choose to interact with others based on little information. Furthermore, these studies have not examined whether acrophily is associated with animosity toward one's political out-group. Using a combination of a survey experiment (N = 388) and an analysis of the retweet network on Twitter (3,898,327 unique ties), we find evidence for users' tendency for acrophily in the context of social media. We observe that this tendency is more pronounced among conservatives on Twitter and that acrophily is associated with higher levels of out-group animosity. These findings provide important in- and out-of-the-lab evidence for understanding acrophily on social media.

Partisans hold inaccurate perceptions of the other side. What drives these inaccuracies? We address this question with a focus on partisan animosity meta-perceptions (i.e. how much a partisan believes opposing partisans hate them). We argue that predictors can relate to meta-perceptions statically (e.g. at a specific point in time, do partisans who post more about politics on social media differ in their meta-perceptions relative to partisans who post less?) or dynamically (e.g. does a partisan who increases their social media political posting between two defined time points change their meta-perceptions accordingly?). Using panel data from the 2020 US presidential election, we find variables display distinct static and dynamic relationships with meta-perceptions. Notably, between individuals, posting online exhibits no (static) relationship with meta-perceptions, while within individuals, those who increased their postings over time (dynamically) became more accurate. The results make clear that overly general statements about meta-perceptions and their predictors, including social media activity, are bound to be wrong. How meta-perceptions relate to other factors often depends on contextual circumstances at a given time.

Polarization poses a critical threat to the stability of nations around the world, as it impacts climate change, populism, democracy, and global health. This perspective examines the conceptual understanding, measurement challenges, and potential interventions for polarization. Our analysis highlights the distinction and interactions between the individual and collective levels of polarization, conceptually, methodologically, and in terms of interventions. We conclude by pointing out future directions for understanding polarization and highlighting the interrelations between polarization and other social phenomena.

Misinformation represents a vital threat to the societal fabric of modern economies. While skills interventions to detect misinformation such as de-bunking and prebunking, media literacy, and manipulation resilience have begun to receive increased attention, evidence on de-biasing interventions and their link with misinformation vulnerability is scarce. We explore the demand for misinformation through the lens of augmenting critical thinking in an online framed field experiment during the 2022 Presidential election in Colombia. Data from roughly 2.000 individuals suggest that providing individuals with information about their own biases (obtained through a personality test) has no impact on skepticism towards news. But (additionally) showing participants a de-biasing video seems to enhance critical thinking, causing subjects to more carefully consider the truthfulness of potential misinformation.

Empathy is considered one of the most critical components for bridging political divides and reducing animosity between political groups. Yet, empathy between political opponents is rare. There is a growing concern that partisans do not empathize with out-partisans because they feel social pressure from fellow in-partisans not to do so. This article examines this social pressure hypothesis and draws two conclusions. First, on the surface, the hypothesis seems plausible: citizens perceive fellow in-partisans as comparatively disapproving of and reluctant to engage in out-party empathy, and naïve cross-sectional analyses suggest that this perception translates into lower empathy towards out-partisans. Second, however, experimental data suggest that this relationship is not causal. Expecting disapproval from fellow in-party members for empathizing with out-partisans does not lead to a significant reduction in intentions to empathize with out-partisans. Rather, exploratory analyses suggest that social pressure by the in-party increases empathy toward out-partisans and triggers disappointment toward in-partisans. This implies that partisans can resist social pressure from the in-party and might even compensate for in-partisans' lack of out-party empathy. The results are supported by original cross-sectional and experimental survey data ( $N=\mathrm{2,535}$ ) collected in the United States, an arguably most likely case for in-party social pressure to shape partisans' intentions. The results have important implications for understanding the causes of and viable strategies for building empathy across political divides.