Most economic models are based on the self-interest hypothesis that assumes that material self-interest exclusively motivates all people. Experimental economists have gathered overwhelming evidence in recent years, however, that systematically refutes the self-interest hypothesis, suggesting...

Trust and reciprocity have paramount importance in cooperative relationships. The influence of psychological effects such as framing and anchoring on trust and reciprocity has been investigated; however, the impact of an order effect on them is still unexplored. The goal of our study was to...

Indirect reciprocity is one of the major mechanisms driving the evolution of cooperation in human societies. There are two types of indirect reciprocity: upstream and downstream reciprocity. Cooperation in downstream reciprocity follows the pattern ‘You helped someone, and I will help you’,...