Inaccurately Simplified Reporting on Willpower Depletion Research

They had food-deprived subjects sit at a table with two types of food on it: cookies and chocolates; and radishes. Some of the subjects were instructed to eat radishes and resist the sweets, and afterwards all were put to work on unsolvable geometric puzzles. Resisting the sweets, independent of mood, made participants give up more than twice as quickly on the geometric puzzles. Resisting temptation, the researchers found, seemed to have “produced a ‘psychic cost.’”

Based on the reporter’s description, I expected that the chocolate eaters merely tried harder because of the caffeine and sugar (both of which are known to help motivate or support mental labor).


But the actual  study was careful of this (see pg 1254, Method, and Table 1); a no-food no-temptation control group performed the same as the chocolate-indulging group. It was only the radish-eating chocolate-resisters (giving up 40% sooner due to the psychic pain of resisting a fresh-baked-chocolate-chip-cookie temptation).