Roy Baumeister is a Professor of Psychology at Florida State University and the author of Willpower. The key point of the book is that people have an exhaustible supply of mental energy and as it drains, we make increasingly poor decisions.
Not only that, our mental energy is used across all sorts of decisions and is the key reason why Albert Einstein and Barack Obama would always wear the same clothes and eat the same breakfast – no decision making to drain their energy.
It is also the reason why prisoners, who want their case heard in a parole board do not want the judges to review it right before lunch – the likelihood that the drained judges will simply default to the safe option – not letting them out on parole – is very high.
And finally this says something around when you want to expose your customers to different offers…