Neoteny:
It has long been observed that humans take longer to mature than do chimpanzees. This is called neoteny, and it is not limited to humans, but often appears in biology, the retention of infantile characteristics into more advanced life. And it has long been suggested that this neoteny has something to do with the way we humans are different. There is now more evidence, which carries the argument to a genetic level. (Juvenile Thoughts Charles G. Choi SCIENTIFIC AMERICAN vol. 301 no. 1 July 2009 page 23.)
Many years ago I was visiting my mother, and it snowed. There was nothing unusual about that except that it was Florida. The power grid failed, and with it the lights and the furnace. I soon got a fire going, but the firewood was wet from the snow, and I had a bit of a project bringing wood in and placing it nearish the fire and then moving fuel inward toward the flame to be warm and dry enough to burn in its time. I certainly felt one with the ages. I wondered how long it was that grown men had done exactly the same thing. I was nursing a fire of wet wood to keep my mother warm. In the end I drove off and bought some charcoal briquettes.
For an adult to care for a parent may not be unique to humans, but it certainly is rare elsewhere. It is a case of social neoteny. Young mammals generally bond closely with a mother. It occurs to me that the ability to form permanent close emotional relationships may be the same thing.
I have mentioned previously that monogamy gives humans an ability to survive with far less genetic and other investment in immunity than dogs and chimpanzees sport. Since that reduces mutation pressure and permits us to carry more of different genes, it could account for every evolutionary advance humans have made over our ape kindred.
Of course that leaves open the question of where monogamy came from. Perhaps it came in part along with a neoteny package.
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