Brain Size

[PaleoPhil]

Yes, they were 11% larger than ours. Though there are other explanations for the bigger size of their brains such as the cold-climate/intelligence theory or simple evolution(that is, our body size decreased after that along with the brain-size, and some people claim brain-size/body ratio is more of a sign of intelligence than large brains per se(though that is also disputed).

What is interesting is that the Inuit have the largest skulls,. reportedly, of all humans(though again that isn't necessarily a sign of greater intelligence).

Wow! Why didn't you mention this before, Tyler? This is huge. I found a reference online indicating that the largest craniums were found among the Greenland Inuit, who happened to have the highest intake of animal foods ever measured among living peoples on the planet (99%). So adult Cro Magnons, Neanderthals (http://blogs.nationalgeographic.com/blogs/news/chiefeditor/2008/09/neanderthal.html), and Greenland Inuit all had cranial capacities larger than adult Neolithic humans. Do the scientists really expect us to believe that's just coincidence?

Another interesting fact is that Neanderthal skulls are no larger than Neolithic brains at birth--but they grew larger than Neolithic brains by adulthood. I wonder if it was the same with Greenland Inuit? If so, it could suggest an environmental effect (such as diet), rather than a purely genetic one.

Here's the confirming reference I found. Granted, it's a fiction book, but it appears to treat this part as historical:

"The French cranium measurers ran into serious problems in Greenland. They were working from the theory that there was a linear relation between a person's intelligence and the size of his skull. They discovered that the [Inuit] Greenlanders, whom they regarded as a transitional form of ape, had the largest skulls in the world." --Peter Hoeg, Smilla's Sense of Snow, pp. 17-18

Why didn't I ever hear about this in school or from the media? I was taught in college that Caucasians were found to have the largest craniums and brains and that racist scientists used this as proof of mental superiority, but that brain size was really not that important after all. I believed that standard line at the time. Not until decades later do I learn that this was apparently false--that the Inuit actually have the largest craniums. Astonishing, but then again, not surprising.

[TylerDurden]

I have mentioned it before, perhaps before your time or on the other group. There are problems re this:- for example, Neanderthals are viewed by anthropologists  as having been less intelligent than modern Neolithic humans, despite having a larger brain-size(though, clearly, they were never the mindless apes they were portrayed as in past decades). And decrease in brain-size could also be due to other factors than meat(eg:- a lack of natural selection pressure in Neolithic(and the tail-end of the palaeolithic) societies as more and more people were able to be kept alive  and breed, who would have died in earlier times).

[PaleoPhil]

I have mentioned it before, perhaps before your time or on the other group. There are problems re this:- for example, Neanderthals are viewed by anthropologists  as having been less intelligent than modern Neolithic humans,

I thought that view had come under dispute recently?

... despite having a larger brain-size(though, clearly, they were never the mindless apes they were portrayed as in past decades). And decrease in brain-size could also be due to other factors than meat(eg:- a lack of natural selection pressure in Neolithic(and the tail-end of the palaeolithic) societies as more and more people were able to be kept alive  and breed, who would have died in earlier times).

Oh, sure, there's no certainty as to the precise cause, but something more than coincidence seems to be at work here. Thanks for the fascinating info.

[wodgina]

Tongues, tonsils, nerves (and brain?) always grow to full size while the cranium may not, imagine the harm that a 11% decrease in cranium size does to a persons quality of life.

How can people think properly with all this muscle/nerves/brain crammed into a small narrow skull?

[TylerDurden]

Tongues, tonsils, nerves (and brain?) always grow to full size while the cranium may not, imagine the harm that a 11% decrease in cranium size does to a persons quality of life.

How can people think properly with all this muscle/nerves/brain crammed into a small narrow skull?

I'm not so sure they remained the same size. For example, the size of teeth also declined with the jaw(the catch is that the number of teeth didn't decline as well, causing modern peoples to sometimes have their wisdom teeth removed). Oh, and brain-size did decline along with body-/skull-size, that's why palaeoanthropologists claim that the body/brain-size ratio of earlier Cro-Magnon is the same body/brain-size ratio as Neolithic Man.

[TylerDurden]

I thought that view had come under dispute recently?

Well, there are alternative viewpoints, the older theory holds that Neanderthals were simply stupider than Man and thus became extinct due to climate/pressure from Cro-Magnon populations etc., another (minority) theory holds that Neanderthal Man were incredibly primitive apemen(looking more like apes than Men) who ate humans and thus speeded up Cro-Magnon evolution(an unlikely theory given the Cro-Magnon penchant for cannibalism). Lastly, there's  the majority viewpoint which states that Neanderthals clearly were intelligent , had a complex culture etc.,but were somehow more disadvantaged than Cro-Magnon peoples, with (usually) the notion being that that disadvantage was slightly lower intelligence.

My point is , though, that if the brain-size/body ratio theory is correct, then the fact that Neanderthals were far more muscular etc. than the Cro-Magnon meant that they had a lower brain-size/body ratio than the latter , and therefore would be less intelligent.

This reminds me of that work of fiction "The Inheritors" where the author William Golding, I believe, suggests that Neanderthals became extinct because they were telepathic and didn't need language/speech like the Cro-Magnon, and the latter is crucial for civilisation to begin. In other words, species can die out even if they have a superior trait to other species, whether that advantage is intelligence or anything else, simply because a positive trait in one circumstance can be beneficial, but highly injurious in another context.

[PaleoPhil]

Interesting new Neanderthal find. Doesn't guarantee that Neanderthals were as intelligent as H. sapiens sapiens, but certainly puts the nail in the coffin of the idea that they didn't have the ability to do symbolic thinking.

Heavy Brows, High Art?: Newly Unearthed Painted Shells Show Neandertals Were Homo sapiens's Mental Equals
A discovery of painted shells shows that Neandertals were capable of symbolism, sweeping away age-old thinking that they were stupid
January 8, 2010
By Charles Q. Choi   
http://www.scientificamerican.com/article.cfm?id=neandertal-art-human

Newly discovered painted scallops and cockleshells in Spain are the first hard evidence that Neandertals made jewelry. These findings suggest humanity's closest extinct relatives might have been capable of symbolism, after all.

.... The rarity of such finds, however, thus far might still suggest to some that Neandertals were not great minds....

Instead of Neandertals and modern humans developing jewelry independently, two intriguing possibilities this discovery raises are that Neandertals taught our ancestors art—or vice versa.

[PaleoPhil]

And now pigments that might have been "makeup" is reported discovered at the same site:

Neanderthal 'make-up' discovered
Did Neanderthals wear make-up?
Scientists claim to have the first persuasive evidence that Neanderthals wore "body paint" 50,000 years ago.
Saturday, 9 January 2010
http://news.bbc.co.uk/2/hi/science/nature/8448660.stm

[Matt51]

Most feel Neanderthals had speech. They had a gene for red hair. Their spear technology (stabbing only) was inferior to "modern man's" throwing spear technology. They may have been more intelligent, no one really knows for sure. They were much stronger, and needed twice as many calories a day, so they had to eat a lot of meat. This calorie requirement may have been a disadvantage in lean times.

[William]

I was taught in college that Caucasians were found to have the largest craniums and brains and that racist scientists used this as proof of mental superiority, but that brain size was really not that important after all. I believed that standard line at the time. Not until decades later do I learn that this was apparently false--that the Inuit actually have the largest craniums. Astonishing, but then again, not surprising.

"It ain't what you got, it's what you do with it"

We see proof of that old saying every day in this forum. The mythic form is the Hellenic story of the hare and the tortoise.

[PaleoPhil]

Brain size is of course not the only factor in intelligence, and I don't know of any scientist of any credibility that argues that, but there is some evidence for it being a factor:

Big-brained people are smarter: A meta-analysis of the relationship between in vivo brain volume and intelligence
http://www.sciencedirect.com/science/article/pii/S0160289604001357

"Based on 37 samples across 1530 people, the population correlation was estimated at 0.33. The correlation is higher for females than males. It is also higher for adults than children. For all age and sex groups, it is clear that brain volume is positively correlated with intelligence."

...though others disagree with the efficacy of that study:  

Many researchers, however, disagree with McDaniel’s conclusion. His research, published in 2005 in the journal Intelligence, suggested that across all age and sex groups, brain volume is linked to intelligence.

Men are smarter than women, according to research published in 2006, which the study researchers say could be due to men having relatively larger brains, a difference of about 0.2 pounds (100 grams). Another scientist put forth several socio-cultural factors that would make the men-smarter results null. http://inc01.com/2011/03/does-brain-size-effect-on-intelligence/

[PaleoPhil]

Harvard evolutionary biologist Prof. Daniel Lieberman provided this and other interesting quotes in today's New York Times:

There are "special features in the human neck that enable us to keep our heads still. That gives us an evolutionary advantage because it helps us avoid falls and injuries. And this seemed like evidence of natural section in our ability to run, an important factor in how we became hunters rather than just foragers and got access to richer foods, which fueled the evolution of our big brains."

Born, and Evolved, to Run
By CLAUDIA DREIFUS
A version of this interview appeared in print on August 23, 2011, on page D3 of the New York edition.
http://www.nytimes.com/2011/08/23/science/23conversation.html?_r=1