Bad
divisive - Causing disagreement or hostility between people, tending to disrupt unity or harmony.

The election was fought over the deeply divisive issue of immigration, and people on either side of the issue can't see things from the other point of view.
dunce - A derogatory term used to ridicule someone who is not very clever, or who does not learn easily.
Being called the dunce of the class motivated Joe to work harder and he finished top of the class. Now sometimes he puts on a joker's costume to make fun of those who used to make fun of him.