IF YOU think kids grow up quickly these days, think again. The uniquely human
habit of taking 18 years or so to mature is a recent development in our
evolutionary history. Growth patterns of fossil teeth have shown that a
prolonged growing-up period evolved long after our ancestors started walking
upright and making tools.
Our great ape relatives, the chimpanzees and gorillas, take about 11 years to
reach adulthood. ¾«¶«´«Ã½s speculate that delaying this process allows children
to absorb our complex languages, culture and family relationships. What’s more,
we need extra time for our large brains to grow—they are half…
