However, as we have said, no single study or series of studies satisfy all of our guiding principles, and these will power experiments are no exception. They all employed small samples of participants, all drawn from a college population. The experiments were contrived—the conditions of the study would be unlikely outside a psychology laboratory. And the question of whether these findings would generalize to more realistic (e.g., school) settings was not addressed.

Nevertheless, the contrast in quality between the two studies, when observed through the lens of our guiding principles, is stark. Unlike the first study, the second study was grounded in theory and identified three competing answers to the question of self-regulation, each leading to a different empirically refutable claim. In doing so, the chain of reasoning was made transparent. The second study, unlike the first, used randomized experiments to address counterclaims to the inference of psychic energy, such as selectivity bias or different history during experimental sessions. Finally, in the second study, the series of experiments replicated and extended the effects hypothesized by the energy theory.


Nearly a century ago, John Dewey (1916) captured the essence of the account of science we have developed in this chapter and expressed a hopefulness for the promise of science we similarly embrace:

Our predilection for premature acceptance and assertion, our aversion to suspended judgment, are signs that we tend naturally to cut short the process of testing. We are satisfied with superficial and immediate short-visioned applications. If these work out with moderate satisfactoriness, we are content to suppose that our assumptions have been confirmed. Even in the case of failure, we are inclined to put the blame not on the inadequacy and incorrectness of our data and thoughts, but upon our hard luck and the hostility of circumstances. . . . Science represents the safeguard of the [human] race against these natural propensities and the evils which flow from them. It consists of the special appliances and methods... slowly worked out in order to conduct reflection under conditions whereby its procedures and results are tested.

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