Q: When do you have to reciprocate a party invitation? I always thought that if it’s a small event in someone’s home, it’s important to reciprocate. What about a payback for having been included in a ...

Reciprocity (give-and-take exchange) is essential for successful human interactions. Feeling motivated to return a favor (and feeling owed for a favor) drives social behavior, personal interaction, ...

Non-human animals consider the value of previously received help when deciding whether to help a social partner, according to a new study in rats. Until now, it was unclear whether animals other than ...