One of the worst psychological pieces of advice on the internet is that which describes resentment as a healthy emotion. Contrary evidence in psychology and medicine notwithstanding, some authors argue that resentment is nevertheless healthy because it "tells you something is wrong." So does disease, emotional disorder, and addiction. There are healthy ways to know that something is wrong and there are unhealthy ways. Resentment is not a discreet emotion; it's an impotent form of anger. Where overt anger motivates aggressive action, the aggression of resentment is mostly in your head, enacted, if at all, predominantly with passive-aggressive behavior, criticism, defensiveness, stonewalling, contempt, or sabotage. Resentment keeps the pump primed for overt aggression, but is not in itself aggressive.