Just to be fair, I get tired of the "teenagers were middle aged" arguments. They are uninformed. People were NOT only living to be 50 way back when. The "average" life expectancy included childhood death which has largely been eliminated now.  Even the Bible says that most humans see 70 or 80 years.  Look through any family tree and you'll see this is so. Early marriage was common because large families were desirable due to agrarian society, NOT because they were dropping dead in their 40s. You couldn't have 8 or 10 kids and be a 35 year old bride, biological clock and all...