Human nature not only has a competitive side to it, which expresses itself through tendencies such as resource striving and status seeking ; it also has an equally important, if not more important, cooperative side which expresses itself through tendencies such as fairness and reciprocity seeking and group identity seeking (for more about this read The dual human nature: competitive and cooperative forces ). Here, I want to focus on one of those cooperative tendencies, namely reciprocity seeking . The principle of reciprocity seeking, which has a strong impact how we behave in social interactions, implies that if someone else does us some kind of favor we want to give a favor in return to that person. Negative reciprocity, by the way, means that if we feel that someone treats us badly, we want to treat them badly in return. In other words, we tend to want to give back what we feel we get.