The Washington Post – Another hurdle is the research on what people actually do after publicly pledging or promising (to themselves, or to others) to engage in some behavioral change. “There’s a lot of evidence on the difference between people making public pledge to do things, and then privately following up on them,” says Craig Parks, a social psychologist at Washington State University. Indeed, there’s experimental evidence suggesting that even when people know they need to cut back on using up resources, they only do so for a short period of time.