Tomenable:European brains are getting smaller for the last 10,000 years - had there been a very strong correlation, it would have meant modern Europeans are dumber than cavemen:
I'm aware that Cro-Magnon, for example, had bigger brains, but they were also brawnier, so you have to factor in the effect of size. However, you're assuming they were not more intelligent, when in actuality their level of intelligence is unknown to us.
Tomenable: East Asian have larger brains than Europeans no matter which method is used:
Well, they also have the highest recorded IQ scores, so I don't see how that advances your argument.
Tomenable:A similar decrease of brain size was observed in domesticated animals:
"(...) The decline of human endocranial volume during the last 10,000 years is paralleled most obviously by the reductions of brain size in domesticated animal species, including dogs, cattle and sheep, compared to their wild progenitors. Nutritional, developmental, and functional issues are all possible explanations for these parallel cases of brain size reduction. (...)"
You might want to take a look at this: Does Domestication Produce Dummies:
http://scienceblogs.com/observations/2010/04/01/domesticated-dummies/
This is a populist analysis of the different points of view with regard to the correlation of brain volume and intelligence:
http://discovermagazine.com/2010/sep/25-modern-humans-smart-why-brain-shrinking
Hawks does indeed think our brains have gotten more efficient.
However, for a contrary point of view...
“You may not want to hear this,” says cognitive scientist
David Geary of the University of Missouri, “but I think the best explanation for the decline in our brain size is the idiocracy theory.” Geary is referring to the eponymous
2006 film by Mike Judge about an ordinary guy who becomes involved in a hibernation experiment at the dawn of the 21st century. When he wakes up 500 years later, he is easily the smartest person on the dumbed-down planet. “I think something a little bit like that happened to us,” Geary says. In other words, idiocracy is where we are now."
"Another popular theory attributes the decrease to the advent of agriculture, which, paradoxically, had the initial effect of worsening nutrition. Quite simply, the first farmers were not very successful at eking out a living from the land, and their grain-heavy diet was deficient in protein and vitamins—critical for fueling growth of the body and brain. In response to chronic malnutrition, our body and brain might have shrunk. Many anthropologists are skeptical of that explanation, however. The reason: The agricultural revolution did not arrive in Australia or southern Africa until almost contemporary times, yet brain size has declined since the Stone Age in those places, too."
"Bailey and Geary found population density did indeed track closely with brain size, but in a surprising way. When population numbers were low, as was the case for most of our evolution, the cranium kept getting bigger. But as population went from sparse to dense in a given area, cranial size declined, highlighted by a sudden 3 to 4 percent drop in EQ starting around 15,000 to 10,000 years ago. “We saw that trend in Europe, China, Africa, Malaysia—everywhere we looked,” Geary says.
The observation led the researchers to a radical conclusion: As complex societies emerged, the brain became smaller because people did not have to be as smart to stay alive. As Geary explains, individuals who would not have been able to survive by their wits alone could scrape by with the help of others—supported, as it were, by the first social safety nets".
“Practically speaking,” he explains, “our ancestors were not our intellectual or creative equals because they lacked the same kind of cultural support. The rise of agriculture and modern cities based on economic specialization has allowed the very brightest people to focus their efforts in the sciences, the arts, and other fields. Their ancient counterparts didn’t have that infrastructure to support them. It took all their efforts just to get through life.”
Tamer but dumber?
"Other researchers think many of their colleagues are barking up the wrong tree with their focus on intelligence as the key to the riddle of our disappearing gray matter. What may have caused the trend instead, they argue, is selection against aggression. In essence, we domesticated ourselves, according to
Richard Wrangham, a primatologist at Harvard University and a leading proponent of this view."
"So what breeding effect might have sent humans down the same path? Wrangham offers a blunt response: capital punishment. “Over the last 100,000 years,” he theorizes, “language became sufficiently sophisticated that when you had some bully who was a repeat offender, people got together and said, ‘We’ve got to do something about Joe.’ And they would make a calm, deliberate decision to kill Joe or expel him from the group—the functional equivalent of executing him.” Anthropological records on hunter-gatherers suggest that capital punishment has been a regular feature of our species, according to Wrangham. In two recent and well-documented studies of New Guinea groups following ancient tribal custom, the ultimate punishment appears to be meted out to at least 10 percent of the young men in each generation. The story written in our bones is that we look more and more peaceful over the last 50,000 years,” Wrangham says. And that is not all. If he is correct, domestication has also transformed our cognitive style."
"For more insight, Hare is now studying other primates, notably bonobos. He tells me he suspects that
these great apes are domesticated chimps. As if on cue, bursts of exotic, birdlike trills suddenly drown out his voice over the phone. “Sorry about that,” he shouts over the line. “Those are the bonobos.” It turns out that as I am speaking to him, Hare is not at his desk at Duke but in a Congo forest where the bonobos live. “Bonobos look and behave like juvenile chimps,” he continues. “They are gracile. They never show lethal aggression and do not kill each other. They also have brains that are 20 percent smaller than those of chimps.”
For yet another theory: Jantz-"His theory: In earlier periods, when famine was more common, people with unusually large brains would have been at greater peril of starving to death because of gray matter’s prodigious energy requirements. But with the unprecedented abundance of food in more recent times, those selective forces have relaxed, reducing the evolutionary cost of a large brain."
were more important.
