This morning I saw a conversation on Twitter and it delivered me a great new insight in intelligence:
Wait? There is a greater male variance in IQ and it has been well replicated? I felt stupid because I didn’t knew. Let’s check the abstract (and the actual paper too of course):
The idea that general intelligence may be more variable in males than in females has a long history. In recent years it has been presented as a reason that there is little, if any, mean sex difference in general intelligence, yet males tend to be overrepresented at both the top and bottom ends of its overall, presumably normal, distribution. Clear analysis of the actual distribution of general intelligence based on large and appropriately population-representative samples is rare, however. Using two population-wide surveys of general intelligence in 11-year-olds in Scotland, we showed that there were substantial departures from normality in the distribution, with less variability in the higher range than in the lower. Despite mean IQ-scale scores of 100, modal scores were about 105. Even above modal level, males showed more variability than females. This is consistent with a model of the population distribution of general intelligence as a mixture of two essentially normal distributions, one reflecting normal variation in general intelligence and one reflecting normal variation in effects of genetic and environmental conditions involving mental retardation. Though present at the high end of the distribution, sex differences in variability did not appear to account for sex differences in high-level achievement.
This graph makes it more clear:
Maybe this isn’t new to you, but if I have ever read it, I didn’t make a mental note of it. But I do see a parallel with what has been called the boy-problem in education. If you look at PISA-reports and reports alike, it’s clear to see that boys have a bigger chance to become a dropout. The past few years there are in many countries more females in higher education than males.
But… if you look at the top students in education, there are males present too, sometimes even still more males than females. Actually, it looks a bit like the charts I just mentioned.
Yes, I know most of the discussions about IQ – btw, you should read the book by Stuart Ritchie – and I’m only suggesting a correlation and no, it doesn’t mean we need to accept that a lot of boys are lost in education. Still, if this is even only a bit true, it’s something interesting to bear in mind.