The Wonderlic is a 50 question test. Although most people find many of the questions easy, you only get 12 minutes which makes getting a perfect 50/50 almost impossible.
To my surprise, the Wonderlic correlated 0.9+ with the big kahuna of IQ tests, the WAIS, in a general population sample, which is really quite incredible for such a short test. In fact it seems too high to be true (maybe it’s an outlier; another study found a much lower correlation among the mentally ill, though the old WAIS was especially good at penalizing the kind of mental illness we find in my comment section ).
I recently cited data from page 6 of this article from no later than the 1970s, suggesting white Americans average 23.32 (SD = 7.5) on the Wonderlic Personnel Test (WPT).
However I worried that the average today might be much higher because of the Flynn effect.
However a 2006 study of production worker applicants found the white mean to be 21.81 (SD = 6.0). This convinced me that scores have not been going up on the Wonderlic in the general population (maybe they’re making the test harder to negate any Flynn effect?). I don’t think they’ve been going down either, but white production workers might be less intelligent than the general white population.
Thus I endorse the following formula for converting Wonderlic scores into IQ (U.S. white norms):
IQ (U.S. white norms) = [(wonderlic score – 23.32)/7.5] + 100
For those who prefer general U.S. norms I endorse the following formula:
IQ (U.S. norms) = [(wonderlic score – 21.75)/7.6] + 100
The second formula is based on a recent academic paper which states:
The average for working adults in the United States is 21.75, with a standard deviation of 7.6 (Wonderlic, 2000)
Some research suggests WPT scores should be adjusted for age in the following way before converting to IQ:
age 16 to 29: Add 0 points to your raw WPT score
age 30-39: Add 1 point
age 40-49: Add 2 points
age 50-54: Add 3 points
age 55-59: Add 4 points
Age 60+: Add 5 points
If you’re well over 60 you’re probably not taking the Wonderlic anyway, but you can extrapolate how many bonus points to add.
Of course some may question whether people taking the WPT are truly representative of Americans or white Americans. I would argue that they’re close enough. Yes, the sample excludes unemployed people who tend to have lower IQs but it also excludes students and rich people who tend to have high IQs, so it perhaps cancels out. And even gold standard IQ tests like the WAIS do not have perfectly representative samples since they exclude the institutionalized and those with psychiatric or substance abuse problems from their norms.
Though the WPT sampling bias might skew the results when estimating the scores of marginalized subgroups where unemployment is high.