The purpose of this chapter is to consider briefly the biological foundations of hurt feelings according to the model in Figure1.1 of this volume. This model emphasizes the circularity of how emotionality is based on various physical levels from the bottom up and from the top down, following principles of equipotentiality and equifinality found in reductionism and interactionism (Buck, 1999; Ochsner & Gross, 2007, pp. 88–89). Simply put, what comes up and emerges upwardly as emotionality from felt feelings becomes emotions when appraised and expressed outwardly, verbally, nonverbally, and in writing. Once experienced inside as feelings and expressed outside as emotions, emotions move downward to the bottom, affecting the organism at molecular and higher levels of functioning – cellular, visceral-muscular, and cerebral – as influenced by attitudes, emotions, and relationships (Hafen, Karren, Frandsen, & Smith, 1996; Stockdale, 2009).

An attempt will be made to include as many levels of Figure 1.1 as there is conceptual and empirical evidence to support them. Within that model, however, we need to include emotionality within a larger context of personality functioning at the various levels included in Figure 1.1.