Washington – On Wednesday, a group of scientists at George Washington University, published in the journal Proceedings of the National Academy of Sciences the results of a study conducted in human beings and chimpanzees. The study focused on trying to reach a better understanding on what makes the human brain more special compared to the brain of our closest living relatives.

Researchers examined the brains of 218 humans and 206 chimpanzees using MRI scans trying to compare them in order to find a clue as to why humans are so capable of adapting to various environments and cultures.

The anatomy of the chimp’s brain is dictated by genetics, while ours, due to its plasticity, is more susceptible to external influences such as the environment and social interactions. Credit: Cutebabywallpapers.com

The findings showed that the human brain has a higher degree of plasticity. This means that because of its malleability, the human brain adapts easily to any environmental change.

The scientists have found that even though humans and chimpanzees have similar brain volume, the structure is very different. The anatomy of the chimp’s brain is dictated by genetics, while ours, thanks to plasticity, is more susceptible to external influences like our family, experiences and social interactions.

Human beings are born with less developed brains, compared to chimpanzees, but its plasticity allows it to progressively grow later as we live and mature with the help of the outside world. Being born with less developed brains is a huge advantage as it will grow to adapt through our learning experiences. Basically, our brain enters the world as a blank canvas ready to grow with experience and not just by genetics.

“We found that the anatomy of the chimpanzee brain is more strongly controlled by genes than that of human brains, suggesting the human brain is extensively shaped by its environment no matter its genetics,” Aida Gómez-Robles, anthropologist from the George Washington University and lead author of the study, said.

After carrying out the MRI scans, researchers created 3-D models of each brain, in order to study them more carefully. The human brains were from twins (identical and fraternal) or siblings; the chimpanzee brains had a variety of relationships, including mothers and descendants or half siblings.

Comparing the brains, chimpanzees from the same family displayed little variation when it came to brain structure, their genes being the most decisive in influencing this particularity. This suggests that the anatomy of the brain in primates is strongly related to genetics, while, in human beings, brain organization was determined to vary significantly, even when subjects shared almost identical genetic inheritance.

Source: PNAS