This paper introduces a group-level perspective on prosocial behaviour by examining how shifting from "I-reasoning" to "We-reasoning" affects sharing in dictator games. Through two experiments, we demonstrate that collective psychological ownership particularly enhances prosocial behaviour, whereas establishing common ground increases sharing likely by strengthening group affiliation. Our findings suggest that fostering "we-reasoning" may effectively enhance prosocial tendencies.

Context effects significantly influence social decision-making, as evidenced in dictator games where dictators' allocation varies between different framing conditions. Our study addresses a gap by comparing three experimental conditions: one where dictators can both give money to or take money from a receiver, one where they can only give money, and one where they can only take money. Results show that the range of available options systematically shifts behaviour—participants are more likely to give when only allocation is possible and more likely to take when only taking is possible. Consideration of social appropriateness significantly reduces taking behaviour, particularly in taking contexts. These findings provide empirical support for Range Frequency Theory in social decision-making.

Punishment is important for preserving social cooperation through normative signalling, but it can also backfire and lead to feuds between parties. This research investigates how common knowledge affects punishment effectiveness using a modified dictator game with varied common knowledge and punishment conditions. Findings suggest punishment is more effective when both parties share common knowledge of norms.

Although lying is typically viewed as antisocial, white lies often serve prosocial functions. We investigate when people consider such deception appropriate or obligatory, finding that white lies function as relationship maintenance mechanisms where individuals prioritise others' benefits over strict honesty. Our research examines how normative social preferences shape deceptive communication intended to benefit others.