The menopause column raised an issue I’ve long wondered about but haven’t seen it directly addressed. Cecil said:
“Average age at menopause today is 51; average life expectancy in 1900 had only reached 47. In other words, during most of evolutionary history, the average woman had enough eggs to last a lifetime.”
Now, what I’m wondering is did Cecil mean “average life expectancy assuming one made it to adulthood” when he said “average life expectancy”? Because my understanding is that one of the reasons life expectancy was so low a hundred years ago compared to today is because the infant and child mortality rate was so high, relatively. This means that when you hear that in 1900 the average life expectancy was 47, it doesn’t mean that people who made it past childhood would reach 47 and drop dead, on average. If they made it to adulthood, they would likely live well beyond 47, though admittedly not to the advanced ages we reach today.
So, it seems to me that the fact that the age menopause generally starts and the average life expectancy 100 years ago are similar doesn’t really mean much, since in reality women who reached adulthood in 1900 would surely live longer than 47 on average.
Now, I will admit that it seems probably true that the average life expectancy assuming one made it to adulthood may have been around 50 “during most of evolutionary history,” as Cecil said, but my post really isn’t arguing about this menopause theory, it’s really wanting to address this often misunderstood notion of average life expectancy.
This is an issue I’ve long thought about because I’ve heard people at social gatherings say things like, “Wow! You’re 35? 1000 years ago you would have been dead!” Well, no. Average life expectancy may have been in the early 30s back then, but again, it doesn’t mean people who reached that age also died around that age on average. Yes the age people died on average assuming they made it to adulthood was much lower way back then, but it was certainly older than the early 30s.