Abstract We possess few laws of behavior. In experimental psychology, the ones we do have largely reflect some form of systematic growth in variation as the mean of a percept or a response grows commensurately. These linear, or often log-linear relationships provide us with important insights. Yet fewer still are behavioral laws that take more curvilinear forms in Cartesian coordinate space. The present work concerns perhaps the most famous of the latter: the inverted-U relationship. Often called the Yerkes–Dodson law, after its supposed originators, it is arguably one of the most famous psychological principles. What of its origins and the solidity of the foundations on which it is grounded, and thus its reliability and subsequent applicability? The present work examines, explores, elucidates, and explains this foundation and illustrates some of the many assumptions and flaws involved in its original promulgation and in some subsequent interpretations, extrapolations, and adoptions. Where, how, and why these associated shortcomings and shortfalls were ignored, overlooked, or blandly accepted leads us to an understanding as to how naive beliefs about behavior populate the psychological world and remain embedded in the very fabric of psychological theory. Notwithstanding these observations, collectively we persist in our belief that humans do poorly at the extremes of overload or underload and peak in our performance at some intermediary level of stress. Why this belief remains the case is the pith of the present work and illustrates how intuition can readily trump factual information in the perception of reality.
P. A. Hancock (Thu,) studied this question.