I'm looking for a word for someone being upset at someone else doing well or succeeding. Either a word for that sort of character trait or a word that describes that behaviour. It could include things like being annoyed at someone trying to make positive changes or something similar. The phrase tall poppy syndrome comes to mind but it's a bit long, and not quite a description of the character.
There are two nouns that define the entire spectrum of the feelings you describe perfectly:
a feeling of discontent or covetousness with regard to another's advantages, success, possessions, etc.
resentment against a rival, a person enjoying success or advantage, etc., or against another's success or advantage itself.
The first adjective that comes to mind when describing one who gets mad at another for doing well is irrational.
For example one could say:
X is an irrational person or demonstrates irrational behaviour by getting upset at person Y when they do well.
Irrational works well here as most reasonable people would not get mad at another person for doing well. Although it may not be fair to deem a person irrational based on the situation described, however one's behaviour is in this case would be considered irrational since most logical decision makers wouldn't see a valid reason to be upset at another for their success. Thus, the person as a whole may be irrational (as well as their behaviour/thinking)
Irrational: Not logical or reasonable.
a hater TFD or hateful
- To feel strong dislike for or hostility toward: rivals who hate each other.
- To feel dislike or distaste for: hates washing dishes; hates to get up early.
He was a hateful person, visibly upset at his friend doing well and succeeding.
Truth is, people confuse jealousy and envy with hate. People who are envious of us don’t hate us, they just want what we have or want to be where we are. But if you don’t address those that are envious of you, the jealousy can ferment into hate. Huffington Post