In the August 2011 edition of the journal Current Biology, the article “Differential Prefontal White Matter Development in Chimpanzees and Humans” describes a study conducted by Japanese researchers that found an increase in brain volume of human babies much more rapidly, early on than in chimpanzee babies; despite that both animals begin life with undeveloped forebrains.
Zoologist Tetsuro Matsuzawa led the study, which was conducted at the Kyoto University in Japan. The team used magnetic resonance imaging technology to scan the brains of three young chimps, starting when the chimps were 6 months old. These scans were then compared with M.R.I. scans taken of human infants and young children. Compiled data shows that the white matter in the prefrontal cortex develops much more rapidly in humans.
The prefrontal cortex is a region of the brain that plays an important role in self-awareness, creative thinking, and decision-making. Growth in the prefrontal cortex is part of what makes humans cognitively advanced. Rapid development of the prefontal cortex in humans could contribute to superior skills in social interaction and communication.
The study also indicates that brain development is shaped by life experience—a potential reason why some human babies and chimp babies share similarities, such as the impulse to smile at caregivers.
Matsuzawa and his team will continue to study brain differences between humans and chimpanzees in young adulthood by tracking the development of the same three chimpanzees observed in the study, which are now 11 years old.