Estimating the IQ of L and Light
In death note, L and Light took a university entrance exam and both topped the rankings with a perfect score. Given the average IQ of college students in the USA is 105 due to selection bias and that Japan has a national IQ of 106, the average IQ of teenagers taking the Japanese college entrance exams is likely to be about 110. Apparently, the university in question is based on tokyo university, which has about 14000 undergraduate students. This means that ~3500 students take this examination every year. top 2/3500 is equivalent to a z-score of 3.25, and within that sample (mean=110, sd=14 - test takers are selected for IQ) that is an SATIQ of 155. Regressed to the mean by the conventional .8 figure used for scholastic achievement tests, that results in an IQ estimate of 146 for both (SE = 8).
A friend sent me that, according to the universe, they both recieved a deviation score of 105, which corresponds to an IQ of 182.5. As I don’t trust >155 estimates, I will just assume they scored above a 165, as the sample was already selected for intelligence. This results in an estimate of 147 with SE = 10.
While this ends the story for Light, this doesn't end it for L. L, besides scoring highly on this assessment, is also the best detective in the world and the most gifted child at the orphanage he was at. So it seems that there are roughly 130000 detectives in the USA - if we assume the number per-capita of detectives is the same in the East Asian and European world, we are left with roughly 700000 detectives who could take the place of the best detective in the world. This is a detective z-score of 4.68 (I’ll just assume he’s above 4); given job performance and IQ correlate at about .58 in highly complex jobs, the simulation indicates he has an IQ of 162 with an SE of 9.1.
Before somebody brings up the manga source that says Near and Light are more intelligent than L, that has been deboonked.