reciprocity
The Manipulative Power of Small Favors: How to Disarm Reciprocity

Reciprocity is both a blessing and a curse, as it fosters relationships, but also exposes us to manipulation
Reciprocity Decay

Our desire to give back wanes rapidly with time - Why if you want people to return a favor, you need to act fast
Gossip and competitive altruism support cooperation in a Public Good game

When there is an opportunity to gain a positive reputation, individuals are more willing to sacrifice their immediate self-interest. Partner choice creates opportunities for competitive altruism, i.e. individuals compete to be regarded as more generous ...
The Surprising Benefits of Gossip

Social scientists are uncovering the intricate group dynamics of gossip