According to S. Epstein's Cognitive-experiential self-theory (CEST), everyone develops an implicit theory of reality that contains subdivisions of self-theory, a world theory, and propositions connecting the two. This theory of reality is a hierarchically organized set of schemes. The most basic schemes, referred to as "postulates", include the degree to which the world is regarded as benign versus malevolent; the degree to which it is regarded as meaningful (including predictable, controllable, and just); the degree to which others are regarded favorably rather than as a source of threat; and the degree to which the self is regarded as worthy, because the basic postulates represent the highest constructs in the hierarchy of personal theory of reality. To invalidate any one of them would have a profoundly destabilizing effect on the entire personality structure. Individual differences in vulnerability to stress (reflected by experiencing positive and negative affectivity) are due, in part, to differences in cognitive representations of the self, more specifically, to differences in the complexity of self-representations. It was assumed that higher self-complexity leads to less affective extremity, and vice versa - low self-complexity is associated with more extreme affective reactions. It was also assumed that high level of complexity was not manifest only in self-concept, but also in particular implicit theories of reality.
