Why did students paid one dollar to call a boring task enjoyable end up believing it, while those paid twenty dollars did not?

Why did students paid one dollar to call a boring task enjoyable end up believing it, while those paid twenty dollars did not?

In 1959, two psychologists at Stanford, Leon Festinger and James Carlsmith, paid young men to lie, and then watched what the lie did to them. The men had just spent an hour on a deliberately dull task. Some were paid one dollar to tell the next person in line that it had been fun and interesting. Others were paid twenty dollars to say the same thing. The result ran against ordinary intuition. The men paid one dollar later rated the boring task a…