Gossip, sharing information about an absent person, is an important way of spreading reputational information, crucial in fostering human cooperation. However, why should information possessors engage in gossip, and why should they be honest? We addressed this question based on a reputational account. In study 1, we found that when observed by potential investors, people were willing to pay more to share reputational information with those in need. Moreover, engaging in gossip did confer reputational benefits for gossipers by receiving more trust from investors, and gossipers' willingness to gossip predicted their subsequent trustworthiness. Study 2 further verified that observability promoted only honest information sharing and deterred dishonest gossiping. Consistently, only honest gossipers were trusted more, while dishonest gossipers were perceived to be even less trustworthy than non‐gossipers, and only the motivation for honest gossiping could reflect gossipers' trustworthiness. These findings suggest that reputation can provide a solution to encourage gossiping and secure honesty.

T here have been rich debates about whether and how mindfulness alters prosocial behaviour. Nevertheless, few empirical studies have touched on how mindfulness training (MT) influences altruistic behaviour under highand low-cost situations in a real-life scenario. The present study aimed to examine the effect of mindfulness training on altruistic willingness at different cost levels. A total of 41 females participated in our study and were randomly assigned to the MT and control groups. They completed the empathy-altruism task and Five-Facet Mindfulness Questionnaire (FFMQ) before and after an 8-week experimental intervention, during which the MT group attended the Mindfulness-Based Cognitive Therapy (MBCT) programme, while the control group remained as usual. The MT group presented a significant increase in overall FFMQ scores after the 8 weeks of MBCT. However, their willingness to help declined in the low-cost situation at post-test. Further analysis revealed a positive correlation between the increase in the scores of the observing facet and willingness to help in the high-cost situation in the MT group. The changes in describing facet were a negative predictor of the change in empathy in the low-cost situation. Taken together, 8-week MBCT enhanced the level of mindfulness but reduced people's willingness to help in the low-cost situation.