Buss and Durkee included this scale because guilt is viewed as a form of auto-aggression—anger directed toward oneself. While it often acts as an internal "brake" for outward rage, it simultaneously creates significant psychological tension and distress.
A healthy level of aggression is necessary for defending boundaries, competing, and achieving goals. It only becomes a problem when scores significantly deviate from the statistical norm, becoming destructive to the individual or their social environment.
A high hostility index (composed of "Resentment" and "Suspicion" scales) leads an individual to perceive hidden malicious intent in a partner's actions. This fosters an atmosphere of constant distrust and emotional strain, even in the absence of overt conflicts.