_Punished by Rewards_ is a great book on the topic. For your experiment, I curious how you controlled for suppressing counter motivations (e.g., peer pressure, pride, etc.)
The class was a required class for teachers to get their education degree. Back then, they had to have that degree in order to teach in the schools.
I doubt that many of them were thrilled for math, especially the more foundational topics we were going through so yes, their intrinsic motivation was mostly not high.
However their extrinsic motivation should have been off the charts. They literally couldn't get their degree without passing the course. Many were repeating the course having failed it before, so their chances were running out.
I do not recall any of the students being the normal 18 to 21 college students - - they were all older. They better understood why they were choosing their degree (looking back, based on demographics, I suspect many were divorcees prepping for a career or moms whose children had started school).
I gave the memorization question as a way to see how much of it was the work they were putting in and much was my inability to explain the difficult material in a way they could understand.
