Understanding, power and trust play a role in every social relationship. If we examine families for instance, we see how (blind) trust develops between the spouses, how they struggle to find agreement on how to raise their children, or how subtle power games emerge so that one partner can bring the other to do what is expected of him or her. In groups—whether they be circles of friends, cliques of adolescents, street gangs, “independent” leftist political groups, or small terrorist cells—we can see how trust (or distrust) develops, how they wrestle with understanding, and how power games arise. Even for small, regular meetings, such as those among grocers, these mechanisms are in play to some extent: a loyal customer may write a letter in an attempt to understand why a product has become so much more expensive, or the customer may threaten (often in unspoken ways) to switch to the newly opened grocer around the corner.