Dan Ariely seems to have the perfect life -- gets paid to think up clever psychology experiments to test people's reactions to certain situations, and then writes popular books about his findings. So any criticism here is probably just envy on my part. Having said that, I find the tone of his books a bit annoying, although that doesn't stop me from flipping through them from time to time. Again, it's probably the envy thing.
Was flipping through his most recent book, "The (Honest) Truth About Dishonesty," which seems to be filled with examples of how "normal" people will "cheat" here and there to get a little extra money. E.g. elderly volunteers will steal money from a gift shop. And experimental subjects will lie on how well they performed on an exercise, in order to get a little extra cash from the experimenters, little realizing that that was the whole point of the exercise.
It turns out that on average, people who do the "matrix" task -- looking at 20 squares like this:
and spotting the pair of numbers that adds up to 10.0 (in this case the 4.81 and 5.19) -- will over-report their ability to spot the sums by about two matrices for a five-minute test, in order to earn an extra dollar (at 50 cents per matrix).
The effect is worse if you've just given them a "depleting task" -- like writing a paragraph without the letter "e", or stating the colors of a series of color-words written in a different color ink (e.g. "red"). If you're "depleted", you'll cheat more.
The researchers seem to translate that into meaning that if you're tired, you'll "cheat" in a non-dishonest sense; e.g. you'll cheat on your diet, you'll procrastinate on your work, etc. In other words, they've taken an interesting finding about dishonesty and converted it into an extremely mundane observation. I didn't need that particular experiment to tell me that I am more likely to succumb to temptation (i.e. break a diet, procrastinate) when I'm tired, when it would require too much exertion (of will) to resist.
I'm not really sure what the result of the experiment shows, but I tend to think it's something different. It has to do with what the subjects thought they had "earned." I can readily see that if I had undergone a frustrating task and then had an opportunity to make a little more money on a different task, I might fudge a bit more, on the theory that I somehow "deserved" the extra cash to make up for the trouble I'd gone through in the depletion task.
He also misunderstands an example he gives on pp. 252-53 about a maid who was stealing meat out of the freezer every few days. The employer's solution was to tell the maid she suspected someone else of stealing the meat, and then to give the maid a key. Miraculously, the stealing stops.
Ariely gives a number of reasons why he thinks it stopped -- (1) the maid had slowly become dishonest over time (finding it easier and easier to steal each subsequent piece of meat), and this gave her the opportunity to "reset" her honesty level; (2) by trusting the maid with the key, the employer managed to change the maid's view toward stealing and thereby established a social norm of honesty in the household; and/or (3) because a key was now needed, stealing was more deliberate, intentional, and harder to self-justify.
Ariely has two phDs and yet these are the best he could come up with.
What's the real answer? Obviously, once you've given the maid the key, that removes all of the other people as suspects. If meat goes missing, it was obviously the maid. I wonder if anyone read this book before it was published?!