Homo sapiens have the longest childhood of any primate. This is due to an evolutionary conundrum.
We have evolved to have large brains in proportion to our body. We also have narrow hips for walking
upright. Narrow hips result in a narrow birth canal. The conundrum is solved by pre-developed
birthing. Offspring leave the womb months before they are capable of walking, skulls and other bones
are still soft, and urinary and fecal control are non-existent. Sexual maturity does not begin until
about 13 and 15 years for females and males. Long childhoods require a considerable investment of
effort by the caretakers, historically mothers. Parents take great pride in their children.