The Trouble With Malcolm Gladwell

This leads to my last topic, the psychology experiment Gladwell deploys in David and Goliath to explain what he means by "desirable difficulties." The difficulties he talks about are serious challenges, like dyslexia or the death of a parent during one's childhood. But the experiment is a 40-person study on Princeton students who solved three mathematical reasoning problems presented in either a normal typeface or a difficult-to-read typeface. Counterintuitively, the group that read in a difficult typeface scored higher on the reasoning problems than the group that read in a normal typeface.

In my review, I criticized Gladwell for describing this experiment at length without also mentioning that a replication attempt with a much larger and more representative sample of subjects did not find an advantage for difficult typefaces. One of the original study's authors wrote to me to argue that his effect is robust when the test questions are at an appropriate level of difficulty for the participants in the experiment, and that his effect has in fact been replicated “conceptually” by other researchers. However, I cannot find any successful direct replications—repetitions of the experiment that use the same methods and get the same results—and direct replication is the evidence that I believe is most relevant.

This may be an interesting controversy for cognitive psychologists, but it's not the point here. The point is that Gladwell makes absolutely no mention of any uncertainty over whether this effect is reliable. All he does is cite the original 2007 study of 40 subjects and rest his case. As I mentioned in my review, in 2013 this is virtual malpractice for a sophisticated writer whose beat includes social science, where the validity of even highly cited results has come into question. Readers who have been hooked by Gladwell’s prose and look to the endnotes of this chapter for a new fix will find no sources for the "hard stuff"—e.g., the true state of the science of "desirable difficulty"—that he claims to be promoting.