What the researchers found, however, says as much about human nature as about the evolutionary basis of patience. Although both chimps and humans preferred six treats to two if they didn’t have to wait, the species made very different decisions when they had to wait. Chimpanzees chose to wait for the larger reward an impressive 72 percent of the time. The Harvard and Max Planck Institute students? Only 19 percent of the time.
— The Willpower Instinct (Kelly McGonigal), Loc. 2382–5