I’ve posted about the IQ of Homo Erectus before, but in this post, I will refine my analysis in light of better understanding.
Experiments suggest that it’s not until a child is seven that she has the mental capacity to create the kind of stone tools Homo erectus created. In other words, Homo erectus may have had the intelligence of a Western seven-year-old. On the WISC-R IQ test, an incipient adult (age 16.9) who performs like a seven-year-old on the spatial construction subtest scores lower than 99.5% of biologically normal members of his generation. In other words, an IQ of about 60.
But we should keep in mind that the research on seven-year-old tool making ability was published in 1979. Probably because of better nutrition/health,truly culture reduced spatial skill has been improved by about 0.2 points a year until 2006 (when U.S. nutrition gains seem to have ended). So Homo erectus probably had an IQ around 55 on the most recent culture reduced Western norms (U.S. white norms).
Brain size of Homo erectus
According to research cited by scholar Richard Lynn, Homo erectus emerged 1.7 million years ago with an average brain size of 885 cc and by 200,000 years ago, their brains had increased to 1,186 cc.
The below chart shows a line of best fit for the average genetic brain size and the average genetic IQ for 13 contemporary human races.
If we extend the trend line to extinct Homo species like Erectus, and if we assume Erectus reached their genetic potential for brain size and IQ (early hunter/gatherers living their natural life style seemed to have far better nutrition than all but the most recent First World agriculturalists and Erectus eventually learned to cook its food, digesting even more nutrients) then we can estimate from their brain size that they had an IQ of about 30, when they first appeared 1.7 million years ago, and about 62 when they were finally killed off by anatomically modern humans. On the other hand, based on their lack of tool progress, they never progressed beyond a mean IQ of 55.
Pumpkin Person 
If only the next page weren’t cut off of that preview. Looks like another boom I’ll have to buy.
And why do you cite Lynn on erectus when there are better people to cite, such as Daniel Lieberman? The number for his cc isn’t wrong, just Lynn is a psychologist.
Please provide source for erectus brain hitting 1200 cc 200kya. Never heard that. I see their average between 8 and 900 cc, not 1200.
Homo erectus hair was (most) probably straight to have had straight hair descendants forming the bulk of his descendants….jus sayin
Nope. The first humans had Afros. Straight hair didn’t evolve until modern humans left Africa.
Like your post. That seems about right though their brin was structurally different so IDk if it really is accurate or not.
To be fair frizzy, afro like hair is a progressive trait. Apes and whites/asians have straight hair while africans do not, this is because african hair provides ventilation when running or doing other tasks that involve burning massive calories. That’s why whites and asians evolved the trait again when they went into a colder environment.
PP,
On block arangement I got 125 which is a culture reduced test, yet my performance is still 103 I think you told me before. I was wondering what you think of this? What is block design measuring? I think I would get a very low score on the draw a man test because I don’t practice drawing. My sister can draw photrealistic drawings but she watches lots ot tv and is very emotional. I read alot, I just finished reading chapter ten of Carl Jungs book on Types, I finaly understand it. And could you expand on cognitive development. If erectis had the mind of a 7 year old does this mean that high IQ people are more mature / more adult than avarage people?
On block arangement I got 125 which is a culture reduced test, yet my performance is still 103 I think you told me before. I was wondering what you think of this? What is block design measuring?
It’s about an equal mix of spatial ability and general intelligence.
If erectis had the mind of a 7 year old does this mean that high IQ people are more mature / more adult than avarage people?
They’re cognitively more developed.