Way back in the 1980s at Vassar College in Poughkeepsie NY I took social psychology. I designed experiments about assertiveness versus aggressiveness. The basic study which other students got some credit for participating in for less than an hour involved filling in pages of easy addition problems.
I wanted to see how long they would go (up to about 20 min I think...) when given simple instructions to do the pages...I wanted to see how long they would do it and then how they would request or demand that they stop if they found it too tedious.