(Not surprising, really, since “to decide” literally means “to cut off” or “to kill” … from Latin dēcīdere, to cut off: de– + caedere, to cut, hew, strike, kill. It’s hard work.)
“Imagine, for a moment, that you are facing a very difficult decision about which of two job offers to accept. One position offers good pay and job security, but is pretty mundane, whereas the other job is really interesting and offers reasonable pay, but has questionable job security. Clearly you can go about resolving this dilemma in many ways. Few people, however, would say that your decision should be affected or influenced by whether or not you resisted the urge to eat cookies prior to contemplating the job offers. A decade of psychology research suggests otherwise.”
Decision-making and prolonged focus both use the brain’s “executive function,” which “draws upon a single resource of limited capacity in the brain.”
What makes choosing so tiring (it’s hypothesised) are commitment and tradeoff resolution.
Commitment: “Committing to a given course requires switching from a state of deliberation to one of implementation. In other words, you have to make a transition from thinking about options to actually following through on a decision. This switch … requires executive resources.”
Tradeoff Resolution: “The mere act of resolving tradeoffs may be depleting. For example, in one study, the scientists show that people who had to rate the attractiveness of different options were much less depleted than those who had to actually make choices between the very same options.” [This sounds exactly like commitment to me …]
- When the brain’s executive function is drained, we may make very different choices than when it’s not. One study found that the choices made when the brain’s executive resources were depleted followed a pattern: the decisions were “reliant on more a more simplistic, and often inferior, thought process.” People made worse decisions.
- We can “take this knowledge into account when making decisions. If we’ve just spent lots of time focusing on a particular task, exercising self-control or even if we’ve just made lots of seemingly minor choices, then we probably shouldn’t try to make a major decision.”
A number of examples of how decision-making suffers when the executive resource is over-taxed are in the article, “Tough Choices: How Making Decisions Tires Your Brain” by On Amir in Scientific American (22 July 2008).
This research reminds me of the recent findings on distraction and impartiality. In that case, remember, when subjects’ cognitions were constrained by having to memorize long strings of numbers (prolonged focus, taxing the executive resource ?), the subjects became impartial in their judgments, seemingly unable to construct arguments to justify acting with self-favouritism or partiality.
Perhaps the same mechanism described above is at work there, but with the result that making choices using a tired executive resource may be said to lead to better decisions (if you think impartiality is better) ?