Puzzled scientists are debating when the shrinking brains of humans is a sign we’re growing dumber or that evolution is making the important thing motor leaner and more efficient.
The average size of modern human brains has decreased about 10 percent over the past 30,000 years from 1,500 to at least one,359 cubic centimeters, how big a tennis ball, reports the AFP news agency.
The brains of females, which are typically smaller than those of men, also have experienced an equivalent stop by size. These measurements were taken using skulls found in Europe, the center East and Asia.
“I’d called that a significant downsizing in an evolutionary eye blink,” John Hawks from the University of Michigan told Discover magazine. Other anthropologists however, observe that brain shrinkage isn’t surprising as the stronger and larger we are the greater gray matter we need to control this larger mass.
The Neanderthal, a cousin of the modern human who disappeared about 30 millennia ago was much more massive coupled with a larger brain. The Cro-Magnons were the Homo sapiens using the biggest brain. They were also stronger than their modern descendants.
David Geary, a psychology professor at the University of Missouri reports these traits were necessary to survive within the hostile environment of the distant past. He has studied the evolution of skull sizes 1.9 million to 10,000 years of age as our ancestors and cousins lived in an increasingly complex social environment.
Using population density like a measure of social complexity, Geary and his colleagues hypothesize the more humans are living closer together, the higher the exchanges between groups, the division at work and also the rich and varied interactions between people.
Finding that brain size decreased as population density increased, Geary tells AFP, “As complex societies emerged, the mind became smaller because individuals weren’t required to be as wise to stay alive.”
Downsizing however does not mean modern humans are dumber than their ancestors instead, they developed more sophisticated forms of intelligence, said Brian Hare, a helper professor of anthropology at Duke University. He noted that the same phenomenon could be observed in domestic animals compared to their wild counterparts.
Huskies might have smaller brains than wolves, but they’re smarter and much more sophisticated. Huskies can understand human communicative gestures, behaving much like human children.
“Although the chimps possess a larger brain (compared to bonobo, the nearest extant relative to humans), although a wolf has a bigger brain than dogs, dogs are much more sophisticated, intelligent and flexible, so intelligence is not perfectly linked to brain size,” Hare told AFP.
Humans have characteristics from both the bonobo and chimpanzee, that is more aggressive and domineering. “The chimpanzees are violent simply because they want power, they struggle to have control and control of others while bonobos are using violence to prevent one for dominating them,” Hare continued.
“Humans are both chimps and bonobos within their nature and the question is exactly how should we release more bonobo and fewer chimp.”