Many scientific studies, though, pull from the vast pool of Psych 101 students required to participate in studies for class credit. The things people will do for class credit are…well, let's just say we're surprised.

For one, they consent to have their arms shaved and let bedbugs crawl around on them. For another, they listen to interminable knock-knock jokes with the punny bits taken out. And let’s not forget the study where college students were directed to wear bathing suits and then made to feel self-conscious about their bodies.

Hope that course credit was worth it.