Clinical evidence suggests that mindfulness meditation reduces anxiety, depression, and stress, and improves emotion regulation due to modulation of activity in neural substrates linked to the regulation of emotions and social preferences. However, less was known about whether mindfulness meditation might alter pro-social behavior. Here we examined whether mindfulness meditation activates human altruism, a component of social cooperation. Using a simple donation game, which is a real-world version of the Dictator's Game, we randomly assigned 326 subjects to a mindfulness meditation online session or control and measured their willingness to donate a portion of their payment for participation as a charitable donation. Subjects who underwent the meditation treatment donated at a 2.61 times higher rate than the control (p = 0.005), after controlling for socio-demographics. We also found a larger treatment effect of meditation among those who did not go to college (p < 0.001) and those who were under 25 years of age (p < 0.001), with both subject groups contributing virtually nothing in the control condition. Our results imply high context modularity of human altruism and the development of intervention approaches including mindfulness meditation to increase social cooperation, especially among subjects with low baseline willingness to contribute.Cooperation is an essential behavior in constructing and maintaining human societies and the past two decades of cognitive neuroscience and behavioral economics experiments have improved our understanding of neurophysiological bases of such behavior. Neuroimaging suggests that cooperation is associated with reward-processing brain areas including rostral anterior cingulate cortex (rACC) 1 , which is known to modulate fear processing in amygdala 2 ; as well as the ventromedial prefrontal cortex (vmPFC), nucleus accumbens (NACC), and caudate 3-5 . Recent research gives us an even more granular view of the pathways involved, showing that "pay-it-forward" indirect reciprocity (altruism without expectation of returned favor, which underlies large-scale cooperation, specifically based on empathy and other-regarding social preferences rather than reputation) is associated with activation of the anterior insula (AI), which in turn regulates the caudate 6 .Cooperation can be generally defined as individual behavior whereby "one individual pays a cost for others to receive a benefit" 7 . Cooperation can be further modelled as equilibrium of games where subjects still act in their self-interest but their utility function (a function that defines individual preferences of given scenarios) includes social preferences that have been modelled in various ways, such as inequity aversion, a second utility function over others ' well-being, etc 8-10 . In the present study we focus on the act of making a private decision regarding what proportion of payment to keep for oneself and what proportion to make as a charitable donation, which is a form of indirect reciprocity or generalized altruism....

As individuals and political leaders increasingly interact in online social networks, it is important to understand the dynamics of emotion perception online. Here, we propose that social media users overperceive levels of moral outrage felt by individuals and groups, inflating beliefs about intergroup hostility. Utilizing a Twitter field survey, we measured authors' moral outrage in real time and compared authors' reports to observers' judgments of the authors' moral outrage. We find that observers systematically overperceive moral outrage in authors, inferring more intense moral outrage experiences from messages than the authors of those messages actually reported. This effect was stronger in participants who spent more time on social media to learn about politics. Pre-registered confirmatory behavioral experiments found that overperception of individuals' moral outrage causes overperception of collective moral outrage and inflates beliefs about hostile communication norms, group affective polarization and ideological extremity. Together, these results highlight how individual-level overperceptions of online moral outrage produce collective overperceptions that have the potential to warp our social knowledge of moral and political attitudes.