Tough to answer when you consider that until just recently (last few hundred years) most Western cultures were getting married at 14, and having their first children around 16.
That puts it in perspective a bit for me. There is no right answer to your question when everyone knows that if this were the Congo, or we were still living based on a culture that hadn't changed much the past thousand years, we'd all be fucking like rabbits by 14-15 max.
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