Dr. Martin Hash Podcast

Vindictiveness is on the fringe of human emotions, usually the result of a personality disorder such as Narcissism or Borderline: typified as self-destructive, paranoid, with a lot of repressed aggression. It's especially prominent during an individual's climbing of the social hierarchy, ultimately as it pertains to mating opportunities but also while seeking control over their own lives. They are often frustrated in their attempts by other individuals with similar motives. When that happens, vindictive people make the thwarting of their ambitions personal, as if the person who brushed past them did it intentionally, and resolve to get revenge.

Even if the cause is real, vengeance, the active part of vindictiveness, goes beyond punishment as retribution for an illegal act. Vengeance is emotional, pathological even, outside the law; it's not rehabilitative, nor protective, serves no valid societal function, and should be discouraged and avoided. Unfortunately, vindictiveness can also be triggered by envy, jealously & resentment. These perceived slights often lead to long-term grudges, sometimes without the other person even knowing they are the focus of the hostility, which is why some paranoia is always justified when you suspect others may be working against you because they actually may be.