Shared life: When we began to change our social gifts

Our culture changed fundamentally when we started to mate for life. I haven't read any dating of this but, I'll guess mating for life started around the time of art, spirituality, language and larger groups (150-200 adult individuals or more) cooperating. I'll also guess that the true shared life is only possible when, to paraphrase Rilke, "we become the guardian of each other's solitude." 

To put this period in perspective, I'll guess it started to emerge from the large brained creature living between 200, 000 and 70,000  years ago. I think mimicry had had its effect on our brains. I think the corpus collosum was sufficiently developed and sexually dimorphous that our social needs met our phenotype needs to push us to mate-for-life scenarios. (it would be interesting to study brains of other mate-for-life creatures and compare them to us alongside our fidelity rates could make a really interesting graphic.) In short, I believe that we learned to live with another for life over an evolutionarily brief period starting about 200,000 years ago lasting to about 70,000 years ago.

I believe we learned our amazing ability to "see the world thru others eyes" during this critical period. Two solid ice ages put us in the mood to mate for life. And, why not? It's an easy way to make and care for offspring that you're "sure or pretty sure are yours." This is also the beginning of our top notch empathy skills (I wrote about empathy in May) Our shared life is our interconnected life. We become dependent and humans are no longer solely individuals. We cannot really be evaluated or judged without consideration for our place in society. 

Sharing life with others is truly a gift we must always give and give well!