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Human Brain Shape Has Hardly Changed

Photo credit: dynamosquito from France, CC BY-SA 2.0 , via Wikimedia Commons.

The changes in human heads over the past 160,000 years were not driven by a changing brain, researchers say. It was the human face that changed, according to a recent article at New Scientist:

Comparing the braincases of early modern human children with adults for the first time allowed the researchers to isolate the brain’s role in the evolution of the skull. The team was surprised to find that while the size and proportions of the skulls of H. sapiens children from 160,000 years ago were largely comparable to children today, the adults looked remarkably different to those of modern adults, with much longer faces and more pronounced features.

Human faces continue to grow until the age of around 20, but the brain reaches around 95 per cent of its adult size by age 6. 


Curiously, age 7 is widely considered to be the age of reason, the point at which a child can clearly understand concepts like right and wrong, as well as the difference between reality and make-believe. In any event, the researchers suggest that the change in human faces over time could stem from a different diet (less chewing) or less need for oxygen.

During the same time period — one of spectacular intellectual achievements — human brains shrank in size.

That said, we are always discovering new things about the human brain. Here are three interesting ones to ponder:

What’s Inside the Brain Is Immense

“Processing so many kinds of information requires many types of neurons; there may be as many as 10,000 types of them. Processing so much information requires a lot of neurons. How many? Well, ‘best estimates’ indicate that there are around 200 billion neurons in the brain alone! And as each of these neurons is connected to between 5,000 and 200,000 other neurons, the number of ways that information flows among neurons in the brain is so large, it is greater than the number of stars in the entire universe!” – The Mind Project

The human brain is said to be the most complex organized thing in the universe and to be similar in organization.

How Many Thoughts per Minute?

One research group tried to work it out: “The average person has about 48.6 thoughts per minute, according to the Laboratory of NeuroImaging at the University of Southern California. That adds up to a total of 70,000 thoughts per day.” – In light of the numbers, we should all hope that not too many of our thoughts were obsessing about stuff that doesn’t really matter.

Read the rest at Mind Matters News, published by Discovery Institute’s Bradley Center for Natural and Artificial Intelligence.