Why do people cheat?

There is always gonna be a reason behind every cheating act. For example, students cheat on their exams to pass as well as to get good grades. You know, when we have good grades, we'll have a high chance in being accepted in whatever job we apply for. Teacher might help their students to cheat. For example, in the U.S., if students under the supervision of a teacher academically perform well, that teacher will get benefits in form of honor, promotion, extra pay as well as credit. However, if the students do the opposite of what has been said above, the teacher will be fired. So, cheating depends on incentives, in other words, the result of something.