The idea that core affect is but one component of the emotion led to a theory called “psychological construction.” According to this theory, an emotional episode consists of a set of components, each of which is an ongoing process and none of which is necessary or sufficient for the emotion to be instantiated. The set of components is not fixed, either by human evolutionary history or by social norms and roles. Instead, the emotional episode is assembled at the moment of its occurrence to suit its specific circumstances. One implication is that all cases of, for example, fear are not identical but instead bear a family resemblance to one another.