After my post last week about what goes wrong when students self-report their grades, the Assistant Village Idiot left a comment wondering about how this would look if we changed the topic to IQ. He wondered specifically about Quora, a question asking/answering website that has managed to spawn its own meta-genre of questions asking “why is this website so obsessed with IQ?“.

Unsurprisingly, there is no particular research done on specific websites and IQ self-reporting, but there is actually some interesting literature on people’s ability to estimate their own IQ and that of those around them. Most of this research comes from a British researcher from the University College London, Adrian Fuhrman.  Studying how well people actually know themselves kinda sounds like a dream job to me, so kudos to you Adrian. Anyway, ready for the highlights?

1. IQ self estimates are iffy at best One of the first things that surprised me about IQ self-estimates vs actual IQ was how weak the correlation was. One study found an r=.3, another r=.19.  This data was gathered from people who first took a test, then were asked to estimate their results prior to actually getting them. In both cases, it appears that people are sort of on the right track, but not terrific at pinpointing how smart they are. One wonders if this is part of the reason for the IQ test obsession….we’re rightfully insecure about our ability to figure this out on our own.
2. There’s a gender difference in predictions Across cultures, men tend to rank their own IQ higher than women do, and both genders consistently rank their male relatives (fathers, grandfathers and sons) as smarter than their female relatives (mothers, grandmothers and daughters). This often gets reported as male hubris vs female humility (indeed, that’s the title of the paper), but I note they didn’t actually compare it to results. Given that many of these studies are conducted on psych undergrad volunteers, is it possible that men are more likely to self select when they know IQ will be measured? Some of these studies had average IQ guesses of 120 (for women) and 127 (for men)….that’s not even remotely an average group, and I’d caution against extrapolation.
3. Education may be a confounding factor for how we assess others One of the other interesting findings in the “rate your family member” game is that people rank previous generations as half a standard deviation less intelligent than they rank themselves. This could be due to the Flynn effect, but the other suggestion is that it’s hard to rank IQ accurately when educational achievement is discordant. Within a cohort, education achievement is actually pretty strongly correlated with IQ, so re-calibrating for other generations could be tricky.  In other words, if you got a master’s degree and your grandmother only graduated high school, you may think your IQ is further apart than it really is. To somewhat support this theory, as time has progressed, the gap between self rankings and grandparent rankings has closed. Interesting to think how this could also effect some of the gender effects seen in #2, particularly for prior generations.
4. Being smart may not be the same as avoiding stupidity One of the more interesting studies I read looked at the correlation between IQ self-report and personality traits, and found that some traits made your more likely to think you had a high IQ. One of these traits was stability, which confused me because you don’t normally think of stable people as being overly high on themselves. When I thought about it for a bit though, I wonder if stable people were defining being “smart” as “not doing stupid things”.  Given that many stupid actions are probably more highly correlated with impulsiveness (as opposed to low IQ), this could explain the difference. I don’t have proof, but I suspect a stable person A with an IQ of 115 will mostly do better than an unstable person B with an IQ of 115, but person A may attribute this difference to intelligence rather than impulse control. It’s an academic distinction more than a practical one, but it could be confusing things a bit.
5. Disagreeableness is associate with higher IQs, and self-perception of higher IQs  Here’s an interesting chicken and egg question for you: does having a high IQ make you more disagreeable or does being disagreeable make you think you have a higher IQ? Alternative explanation: is some underlying factor driving both? It turns out having a high IQ is associate both with being disagreeable and being disagreeable is associated with ranking your IQ as higher than others. This probably effects some of the IQ discussions to a certain degree….the “here’s my high IQ now let’s talk about it” crowd probably really is not as agreeable as those who want to talk about sports or exchange recipes.

So there you have it! My overall impression from reading this is that IQ is one of those things where people don’t appreciate or want to acknowledge small differences. In looking at some of the studies of where people ranking their parents against each other, I was surprised how many were pointing to a 15 point gap between parents, or a 10 point gap between siblings. Additionally, it’s interesting that we appear to have a pretty uneasy relationship with IQ tests in general. Women in the US for example are more likely to take IQ tests than men are but less likely to trust their validity. To confuse things further, they are also more likely to believe they are useful in educational settings. Huh? I’d be interested to see a self-estimated IQ compared to an actual understanding of what IQ is/is not, and then compare that to an actual scored IQ test. That might flesh out where some of these conflicting feelings were coming from.