Hostility is seen as form of emotionally charged angry behavior. In everyday speech it is more commonly used as a synonym for anger and aggression.
It appears in several psychological theories. For instance it is a facet of neuroticism in the NEO PI, and forms part of personal construct psychology, developed by George Kelly.
In psychological terms, Kelly considered hostility as the attempt to extort validating evidence to confirm types of social prediction, constructs, that have failed. . Instead of reconstruing their constructs to meet disconfirmations with better predictions, the hostile person attempts to force or coerce the world to fit their view, even if this is a forlorn hope, and even if it entails emotional expenditure and/or harm to self or others. In this sense hostility is a form of psychological extortion - an attempt to force reality to produce the desired feedback, even by acting out in bullying by individuals and groups in various social contexts, in order that preconceptions become ever more widely validated. In this sense, hostility is an alternative response to cognitive dissonance .
While challenging reality can be a useful part of life, and persistence in the face of failure can be a valuable trait (for instance in invention or discovery ), in the case of hostility it is argued that evidence is not being accurately assessed when the decision is made to repeat the same approach . Instead it is claimed that hostility shows evidence of suppression or denial, and is "deleted" from awareness - unfavorable evidence which might suggest that a prior belief is flawed is to various degrees ignored and willfully avoided