Do Wonderlic Tests Predict QB Performance?

Quarterbacks with above median intelligence as measured by the Wonderlic test perform significantly better than those with below median scores according to a report done by Criteria Corporation, an employee testing company.

For QB's drafted between 2000 and 2004 who qualified with at least 1,000 yards, the correlation between Wonderlic scores and total passing yards is r=0.51. For TDs thrown the correlation is 0.49. Those are incredibly strong correlations. As the authors put it, "some of the strongest coefficients reported anywhere in organizational psychology."

Here is their graph of passing yards vs. Wonderlic score. You can see the upwardly sloping trend clearly.

The authors restate their findings, "the QBs who scored below the median Wonderlic score (for QBs) of 27 averaged 5,202 passing yards and 31.2 TDs over their first four years, whereas those scoring above the median averaged 6,570 yards and 40.8 TDs over the same period." Here is their other graph:


The research has some shortcomings, however. By my count there are only 30 qualifying QBs, which is a relatively small sample. The results are still significant, meaning we can be fairly certain the true correlation isn't zero, but it may be somewhat less than 0.5. If you move the qualifying cutoff line to 2000 yds and throw out Tom Brady [33 Wonderlic, 10,000+ yds] the correlations become 0.26 and 0.28. Also, the study uses total yards and total TDs thrown through a QBs first 4 years as its performance metrics. This may may bias the results because some QBs in the data have not yet completed 4 years of play. Plus, even below-average QBs can amass large amounts of total yards and "trash" TDs if their team is frequently behind in the 4th quarter.

I would suggest using a minimum qualifying cutoff of pass attempts, and then use yards per attempt or yards per attempt adjusted for interceptions as the performance metric. The authors generously provided their data so perhaps I'll redo the study with that in mind.

The Criteria Corporation study was itself a reaction to another done by professors at the University of Louisville that reached opposite conclusions. That study is riddled with flaws too numerous to detail. In short however, they used initial salary, draft order, and NFL QB rating rating as performance metrics, used no minimum qualifying standard for inclusion, and limited performance scope to the first 3 career years regardless of how little playing opportunity a player had. It's as if the authors don't understand football at all, or intentionally sought out to discredit any connection between the Wonderlic (or intelligence in general) and performance. (By the way, it's frankly amazing to me how full-fledged PhD researcher types can publish severely flawed studies like this, even after peer review.)

Despite the shortcomings of the Criteria's report, I think the data does suggest there may be a measurable connection between intelligence and QB performance. Bad news for Tennessee fans.

If you're curious how your favorite QB scored on the Wonderlic, here is a site with reported scores through the 2006 draft class. And here is another study on the Wonderlic and QB performance that finds no connection.

I took another more critical look at this study here.

Hat tip to Erik Loken via Statistical Modeling, Causal Inference, and Social Science.