The role of cognitive depletion in how we believe
Faced with too many choices (see Do You Make Too Many Decisions?), people find it difficult to stay focused long enough to handle even routine tasks and decisions.
We have a limited amount of cognitive energy and using it ensures that subsequent tasks are increasingly difficult. Additionally, cognitive depletion makes it easier for others to persuade or manipulate us.
In a 1991 journal article—How Mental Systems Believe—Dan Gilbert wrote:
Throughout the course of history, governments have routinely practiced the art of changing minds. Many of the techniques they have developed trade on the assumption that beliefs are most easily instilled when the believer's cognitive resources have been depleted. Political prisoners, for example, are commonly deprived of sleep because it is through that mental fatigue will facilitate their rapid indoctrination.
As one victim of the Maoist though-reform programs recalled of his own “reeducation” in China, “You are annihilated, exhausted, you can't control yourself, or remember what you said two minutes before. You feel that all is lost. From that moment the judge is the real master of you. You accept anything he syas.”
The prisoner's acceptance is not, of course, limited to those propositions put forth by interrogators or judges. Indeed, a ubiquitous feature of belief-induction programs is the forced confession, a remarkably effective technique that requires resource-depleted prisoners to tell themselves the propositions that their captors wish them to embrace. Prisoners are coerced to write and recite the appropriate political doctrines and, eventually, even the most intransigent prisoner begins to experience some difficulty doubting his or her own words.