[NOTE FROM PUMPKIN PERSON: PLEASE PLACE ALL OFF-TOPIC COMMENTS HERE. THEY WILL NOT BE POSTED IN THIS THREAD]
I’ve posted about the IQ of Homo Erectus before, but in this post, I will refine my analysis based on new information.
Brain size of Erectus
According to research cited by scholar Richard Lynn, Homo erectus emerged 1.7 million years ago with an average cranial capacity of 885 cc and by 200,000 years ago, their cranial capacity had increased to 1,186 cc.
How does this compare to modern white cranial capacity? Anthropologists still cite data from before WWII which is useless because people were short and malnourished back then. The most up to date direct data I could get on white brain size was a 1980 study of autopsied brains at the Case-Western Reserve University’s Medical School in Cleveland, Ohio. At age 25 white male brains averaged 1570 g and white females averaged 1339 g, which I converted to in vivo volumes of 1492 cc and 1273 cc respectively, for a sex-combined white mean 1383 cc.
People use the terms brain size and cranial capacity interchangeably, but the reality is that much of your intracranial volume is cerebrospinal fluid cushioning your brain from blows to the head. Indeed when I looked at the brain volume/intracranial volume ratio for control subjects in table II of this study, I found it to be 0.906, which means the sex-combined white brain volume of 1383 cc I cited above, needs to be divided by 0.906 to get the sex-combined cranial capacity, which is 1526 cc. And the within race, within sex, standard deviation for cranial capacity appears to be about 91 cc ( see table 1 of Rushton’s data), which means that when Erectus first appeared with their 885 cc heads, they were 7.04 SD smaller brained than today’s whites, but by the end of their run when they were 1,186 cc, they were 3.74 SD smaller brained than today’s whites.
The 0.45 correlation between IQ and brain size suggests that for every 1 standard deviation increase in brain size, IQ is expected to increase (on average) by 0.45 standard deviations, so when Erectus was 7.04 SD smaller brained than today’s whites, their expected IQ was 7.04 SD(0.45) = 3.17 SD lower than modern whites. Since whites by definition have a mean IQ of 100 with an SD of 15, this gives early Erectus an expected IQ of 52.
However towards the end of its run, Erectus was only 3.74 SD smaller brained than today’s whites, implying an IQ that was only 3.74 SD(0.45) = 1.68 SD lower. In other words an IQ of 75.
How well does brain size predict the fossil evidence for cognitive ability?
The IQ of Homo erectus
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). This is about the IQ predicted from the brain size of early erectus, however it’s well below the IQ 75 predicted for bigger brained later erectus.
Either erectus had other brain deficiencies that prevented their IQs from rising above the 50s despite increasing size, or they made more sophisticated tools later in their existence that I’m not aware of.
If I can keep 27 things in mind at the same time and pumpkin can keep about 60. Homo erectus was able to keep one thing in mind at any given moment. IQ tests are confusing because we really do not know what they do. But that puzzle with 81 items gave me an idea. If I could not solve it, it was because I can only hold 27 items in mind and not 81 items in mind. Nor move them in my mind. This means a concrete chart can be made of intelligence that is not confusing. A smart person can keep many things in mind.
(1) 1 * 0 items for IQ 55 scale score 1
(3) 3 * 0 items for IQ 70 scale score 4
(6) 6 * 0 items for IQ 85 scale score 7
(9) 9 * 0 items for IQ 100 scale score 10
(27) 9 * 3 items for IQ 115 scale score 13
(54) 9 * 6 items for IQ 130 scale score 16
(81) 9 * 9 items for IQ 145 scale score 19
(108) 9 * 12 items for IQ 160 scale score 21
(126) 9 * 14 items for IQ 170 scale score 24
“” Either erectus had other brain deficiencies that prevented their IQs from rising above the 50s despite increasing size, or they made more sophisticated tools later in their existence that I’m not aware of.””
Maybe the hyoid bone in their necks was in the wrong place and they couldn’t develop as good language skills as us in order to communicate higher concepts. Plus looking at their picture their frontal lobe doesn’t seem to be as well developed as ours, assuming the forehead size is a good indicator for the size of its corresponding lobe. The three lobes of intelligence need to be fully developed IMO.
Excellent points
these articles PROVE that peepee has reified g.
sad!
Actually i didn’t mention the word g in either the last 2 articles. The concepts of intelligence & intelligence testing predate g.
what does this have to do with anything peepee?
binet’s tests were designed to identify people with problems.
And homo erectus would have had problems in the school district Binet was studying
Not if he was given the proper educational supports pumpkin and adequate childhood nutrition. Have you factored in homo erectus nutrition? NO.
All joking aside, erectus was a hunter gatherer so had fabulous nutrition & SES has little effect on truly culture reduced tests
SES has little effect on truly culture reduced tests…
another fact peepee just made up.
or there are no true scotsmen.
How come you didn’t explain that it matters what social economic class homo erectus was born in?
what if homo erectus was focused on basketball instead of his studies?
Wow i never thought of that
what if homo erectus was focused only on how he could impregnate white women?
Should make a post on how personality affects IQ or IQ affects personality instead of useless Homo Erectus estimations. Nobody cares about dead monkeys.
Personality and IQ has confused me such a long time.
People can keep things in mind and move them in new placements.
But it is variable whether they can accept a correct new idea.
or whether they will emotionally react differently choose to solve different problems with their IQ.
One guy, I had so much Oh my God, What the Hell Moments with was that no matter what I said (simulated connection can direct and change information flow with feedback just like the brain to be intelligent) All he could say was that computers cannot be intelligent because a computer can only follow rules. This person was like 125 in IQ — 12 points higher than me.
Pumpkin needs to explain why this 125 person could not understand computers can use feedback loops like the brain to be intelligent. When Animekitty IQ 113 understood this stuff existed from the 1950’s call cybernetics.
Pumpkin Person needs more articles on IQ and personality.
All he could say was that computers cannot be intelligent because a computer can only follow rules.
This person is 125 IQ
What the hell Pumpkin
This is definitely not true
Please do an article on personality and IQ.
Thanks.