One’s social identity tends to lead one to favor those belonging to one’s group; this ingroup bias may lead to problematic relationships. At the same time, communication has been found to have beneficial social consequences in controlled laboratory experiments. An important question is...

Promises often foster trust and cooperation. A recent literature explores why. Two explanations have been proposed, and experimental tests provided some support and some controversy:- Charness & Dufwenberg (2006) (C&D) propose an expectation-based explanation (EBE). People are guilt averse (GA):...