The excellent science writer John Tierney has an essay in the NY Times Magazine about the effects of ego depletion—the idea that self-control is a limited resource that can be depleted the more we use it. The article, which is excerpted from a book he wrote with the social psychologist Roy Baumeister, specifically addresses the fatigue that sets in when we’re faced with choices, which impedes our ability to make good decisions later.
The most interesting part for me was the implications for poor people who have to make choices all day long in terms of how to allocate limited financial resources. We often associate low socioeconomic status with some kind of willpower failure, and consequently make a dispositional attribution: they are weak people, and so they make bad choices. But in fact, this can be a product of the situation: the many difficult choices they have to make all day long.