In the grand, cosmic order of a deterministic universe, there can be no such thing as stupidity to a behaviorist. Behavior is simply (or complexly) caused, and the corruption of the learning process and limitations on a living system's ability to adapt are inherent in the process of life. Organic systems may be maladaptive and do fail, but because of the self-imposed restrictions of science, it is considered improper to interpret such debilitating conditions and events in terms of free choice.
On the other hand, within the microcosm of each particular cultural group, the self-deceptive language/perception complex, a social commitment to norms and pressure toward groupthink all can contribute via the neurotic paradox to setting up a positive feedback system which carries a given learning pattern to self-defeating excess. Contrary to prevailing Darwinian dogma, this normal learning mechanism can render human behavior maladaptive, with different groups of people and individuals commonly vying and dying to display their own particular form of the general phenomenon we call stupidity. Resultant behavior is properly termed stupid when it is justly construed as failing according to and because of the ends (purposes) and/or means (methods and morality) of the reference group.
Thus, not all failures are stupidjust those which betray a compromise commitment to perceptual accuracy and social integrity by going to an unnecessary extreme. As a general principle of cultural life, stupidity is an expression of our inherent disposition to judgespecifically, stupidity indicates a subjectively shaped negative evaluation of predetermined behavior. Stupidity is so common because people characteristically interpret their behavior favorably even if it leads eventually and inevitably to failure. This is the overwhelming lesson of past human failuresthat short-term, self-deceptive misinterpretations of events can induce long-term demise.
We are indebted to those who failed so stupidly in the past, because their mistakes permit us to understand what we are presently doing. More important, we are obliged to acknowledge that our actions will shape the future. An understanding of how stupidity affects human behavior might make us better people or at least more successful at being who and what we are. This understanding places a moral burden on us to be responsible not only for ourselves but also to those poor souls who will pay the price for our next stupid failure and the next...and the next.....