When our daughter was a preschooler, authority figures informed parents that the human brain was fully formed by around five-years-old. After that, there would be no new brain cells, which was why, they told us, the early years were so important. These were the scientific facts. Just a few days ago, a parent of a preschooler told me that the director of her child’s school told the assembled parents that the human brain was “90 percent developed” by five, information which she conveyed to me in a kind of jittery breathiness that betrayed both awe and panic. I recall feeling similarly about these scientific facts. 

The problem with these facts is that they were not facts 20 years ago and they are not facts today. They are the product of a debunked theory about human brain development. Sadly, these non-facts were, and still are, being used to support the toxic academic pressures being applied to our youngest citizens.

It seems that the earlier “facts” were based largely upon studies done on monkey brains in a laboratory. When skeptical scientists more recently tested the theory on monkeys living in their natural habitat they found that not only do their brains continue to produce new brain cells throughout their lives, but they produce a lot of them. It was being held in captivity that caused their brains to stop producing new cells. This has now been confirmed in birds, rats, and other animals, including humans: when animals are free, their brains grow, when they are not free they don’t.

Play is the “natural habitat” of young humans. Traditional schools are, at their core, a form of captivity. Longer school days, more academic instruction, developmentally inappropriate expectations, less time outdoors, standardization, and high stakes testing are causing children’s brains to stop growing. The cure, according to science, is to set our children free, to let them play: that is how brains grow.

******