August 22, 2011
Decision Fatigue And Conservation Of Willpower

NY Times reporter John Tierney and researcher Roy Baumeister have written a book, “Willpower: Rediscovering the Greatest Human Strength”, about Baumeister's area of scientific research: how the brain's performance degrades when it has to make lots of decisions and when it is tired. A New York Times Mag article by Tierney surveys some of the findings from the book. If you make a group of decisions count on the later ones to be of lower quality.

As they started picking features, customers would carefully weigh the choices, but as decision fatigue set in, they would start settling for whatever the default option was. And the more tough choices they encountered early in the process — like going through those 56 colors to choose the precise shade of gray or brown — the quicker people became fatigued and settled for the path of least resistance by taking the default option. By manipulating the order of the car buyers’ choices, the researchers found that the customers would end up settling for different kinds of options, and the average difference totaled more than 1,500 euros per car (about $2,000 at the time). Whether the customers paid a little extra for fancy wheel rims or a lot extra for a more powerful engine depended on when the choice was offered and how much willpower was left in the customer.

When able to do so it is best to order your decisions to make the most important and consequential ones first.

If you go for a buying approach increases the number of decisions you have to make you will make poorer quality decisions overall.

Similar results were found in the experiment with custom-made suits: once decision fatigue set in, people tended to settle for the recommended option. When they were confronted early on with the toughest decisions — the ones with the most options, like the 100 fabrics for the suit — they became fatigued more quickly and also reported enjoying the shopping experience less.

If you really want to take a more complex approach then try to spread your complex set of decisions out over different days. I've been doing that for a belated spring cleaning where I go thru lots of old possessions and ask myself do I really want to keep them. I could do it all in a few days. But I'm doing pieces each weekend over several weeks and and delaying decisions that I'm unsure about.

Another lesson from the article: If you are poorer then making buying decisions is more fatiguing. Buy less stuff and keep more money in your checking account so when you do go to buy you'll suffer less mental exhaustion from it. Living close to the financial edge is mentally exhausting.

Here is a blog post by Tierney on the same topic.

Share |      Randall Parker, 2011 August 22 08:01 AM  Brain Performance

matthew said at August 22, 2011 9:52 AM:

If anyone finds a link to a good summary of this book, please post here.

I have a link to offer in exchange that covers procrastination:

and the whole book:

PacRim Jim said at August 22, 2011 1:25 PM:

Decision fatigue certainly sets in when shopping for electronic devices.
How to choose among thousands of marginally different devices?
I sometimes long for the old days, when there were only a couple of alternatives from which to choose.

Doug said at August 23, 2011 11:09 AM:

As an occasional player in chess tournaments, I am interested in research which may have practical uses in helping me seek wins. Selecting move choices where I will then have relatively obvious moves to make and the opponent has to find good moves in bewilderingly complex situations is a likely path to victory, given decision fatigue. It is one reason chessplayers study openings somewhat obsessively: they are seeking ways to get tricky positions they will already know while their opponent has to walk a veritable tightrope to avoid immediate loss or a lasting disadvantage. There should be other analogous opportunities in competitive situations. Obviously, labor-management negotiations, nuclear arms reduction, international treaties, corporate merger-sale negotiations, etc., have always been sort of like this. Hard bargaining, now plus calculated attempts to create opponent decision fatigue?!

bbartlog said at August 23, 2011 11:43 AM:

Tournament poker players experience the same problem. It's actually quite a good example because in many cases the correct decision is fairly trivial, but if you haven't trained up your endurance in these things you end up losing your ability to make the correct decision after five or six hours of play...

J. Stanton said at August 25, 2011 6:27 PM:

Willpower requires energy -- a fact objectively measurable by the brain's increased consumption of glucose while making difficult decisions.

This article covers the issue in the context of dieting, but the applications elsewhere are obvious:

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