Human Brains Develop Wiring Slowly, Differing from Chimpanzees

Dr. Sherwood and co-authors write that the development of myelin from birth to adulthood in humans is protracted in comparison to chimpanzees. In humans, myelin develops slowly during childhood, followed by a delayed period of maturity beyond adolescence and into early adulthood. In contrast, in chimpanzees, the development of myelin already starts at a relatively more mature level at birth and ceases development long before puberty.

“These observations indicate that a marked delay in the development schedule of the human neocortex may play an important role in the growth of connections that contribute to our species-specific cognitive abilities,” wrote Dr. Sherwood and co-authors.

The developmental timing of myelination is important because it establishes connectivity among parts of the growing brain, which is essential to higher-order cognitive functions, such as decision-making and emotional regulation. These cognitive functions are known to mature relatively late in humans, after the time of adolescence.

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