Although theory suggests individuals are more willing to incur a personal cost to benefit
ingroup members, compared to outgroup members, there is inconsistent evidence in support …

Extensive cooperation among unrelated individuals is unique to humans, who often sacrifice
personal benefits for the common good and work together to achieve what they are unable …

To understand why investors hold socially responsible mutual funds, we link administrative
data to survey responses and behavior in incentivized experiments. We find that both social …

When one individual helps another, it benefits the recipient and may also gain a reputation
for being cooperative. This may induce others to favour the helper in subsequent …

Highlights•People cooperate more when they can choose partners than when partners are
fixed.•Partner choice creates a 'biological market'for the best partners.•Partners are chosen …

We present a lab-field experiment designed to systematically assess the external validity of
social preferences elicited in a variety of experimental games. We do this by comparing …

Trust is a key aspect of various social interactions. Correspondingly, trust has been heavily
studied across different scientific disciplines. However, an integration of the diverse research …

Protecting the environment is a social dilemma: environmental protection benefits everyone
but is individually costly. We propose that protecting the environment is similar to other types …

Among immediate-return societies, cooperative social relationships are maintained despite
the lack of centralized authority, strong norms of ownership and the punishment of free …

Large-scale non-kin cooperation is a unique ingredient of human success. This type of
cooperation is challenging to explain in a world of self-interested individuals. There is …