It can be someone's reaction to injustices or something unfair that has happened in their life. It can also be cause by guilt, someone feeling guilty over something happening that they felt they could have controlled.
References[change | change source]
- D M Marino ed., On Resentment (2013) p. 301-3
- TenHouten, W. D. (2007). General Theory of Emotions and Social Life. Routledge.