In a recent post, I argued that Ted Kaczynski likely had a much lower IQ than you’ld expect from a precocious Harvard educated tenured STEM professor because he ended up living dirt poor without running water and electricity. However in the comment section, blogger Alcoholicwisdom stated:

This is an interesting perspective, because a member of the Prometheus society once told me that there was an optimum IQ for conventional success (about 130) and that people who deviate too far from it (in either direction) tend to be at risk for failure by society’s standards. I’ve always been skeptical of this view, but there’s some evidence to support it, such as the fact that Christoper Langan, declared the smartest man in America, worked as a bar bouncer and ultra-high IQ blogger Rick Rosner repeated the 12th grade over and over again. So it can be hard for normal people to relate to the complex motivations of the profoundly gifted. Just as no normal person would consider it rational to choose to repeat the 12th grade four times as the hyper-gifted Rick Rosner did, perhaps Ted Kaczinsky’s odd choice to give up a prestigious gig in academia to live in extreme poverty might also reflect ultra high IQ logic that few are smart enough to understand.

The problem is that Kaczynski’s test scores on the WAIS-R, while extremely high, were much closer to the putative optimum IQ of 130 than the putative high risk zone (IQ 150+). However, it’s rumored that Kaczynski scored somewhere around 170 on a childhood IQ test, however such scores must be interpreted with great caution because childhood IQ’s from the era were often obtained on tests with old norms using the old mental age/chronological age formula for calculating IQ which can give ludicrously high results at certain ages.

What about Kaczynski’s SAT scores? He was one of the best math students in the country so I think it’s safe to say he had the math talent of a perfect 800+ math score on the old, more difficult SAT. What about his Verbal score? On the WAIS-R he obtained a Verbal IQ of 138, but the test was 15 years old at the time he was tested and Verbal norms are said to expire at a rate of 0.2 IQ points a year, so let’s downgrade his Verbal IQ to 135. According to a chart by the Prometheus society (see section 8.3.3 of this link), a WAIS IQ of 135 equates to an old SAT verbal of 640. Adding this to his estimated Math SAT of 800+ gives a combined score of 1440, which according to the same chart, equates to an IQ around 145. Considering the likely ceiling bumping on the Math section, one could make a credible case for an IQ around 150.