It's wrong to try to upset people on purpose.
Dave learned that his friend Jimmy did poorly on a science test they took.
Dave wants to talk to Jimmy about the test.
Dave tells Jimmy they can study together for the next test.
Dave taunts Jimmy and tells him he has a small brain and won't imrpove.
Jimmy will think Dave is a good friend and motivated to do better.
Jimmy will get angry at Dave and tell him he doesn't want to be friends anymore.