How do I know the chances merely double? Let's say 200 women had babies before they turned 25, and only 50 women had babies afterwards. Even if the same proportion of each group reached 100, more of the babies who reached 100 would have younger moms. For example, if 10 percent of the babies reached 100, 20 of them would have younger moms and 5 of them would have older moms. What you really need to know is how many babies were born to each group, and then what percentage of those babies lived to be 100.

I meant "really" double, not "merely" double.

Women married earlier than they do today, so children were more likely to be born by young mothers. This would skew the statistics right off the bat.

ALso, kids were more likely to die young from diseases. The total mortality of this group is far, far higher than an equivalent group of children today. Result: far fewer people have the chance to live to 100, so what it tells us about our current life expectancy is pretty limited.

Perhaps farmers tended to live longer because the pollution and disease in urban areas contributed to earlier mortality.

There's a really common methodological mistake that these researchers made.

They found some interesting result, then looked a large number of possible explanatory factors, looking for correlation. They can be confident they found it in the mother's age -- 95% confident, in fact. Just a 1/20 chance that they are wrong.

But they looked at a lot of possible factors. If you look at more than 20, you would expect that at least one would show up just due to random chance. Then you get to be excited that you found something, but even though the statistics appear to support your case, what you found is probably just random noise.

It's good grounds for further investigation -- you can run another study that looks just at this one theory. But this shouldn't meet the bar of an announcement to the press. Especially not with the tiny sample size in question.

“Expiration Date”!

At least that what it sounds like, those dam f-ing Conservatives trying to tell me that it’s healthier to have a child when I’m under 25 than when I’m pushing 50. It' just bad science.

IT’S MY BODY DAMMIT!!!!!!

100, jeez. Isn't, like, 85 really enough? After that all your friends are dead, your spouse is dead, your kids have grandkids they're obsessed with and see you as a burden, and your health is failing. I don't see why I should wish that on my child, or change my behavior in any way to foment it.

Am I the only one who _doesn't_ dream daily of living to be 100? I happen to be unfashionably against the idea of motherhood at ages far outside the natural realm of these things (fifty-year-olds with infants? Uh, no), but the idea that we should actually actively be pursuing motherhood in our early twenties *on the off chance that it will allow our children to live to be as old as humanly possible* is just sad. I won't even get into the methodological problems here--the bare notion of the conclusion's implications, however said conclusion is arrived at, leaves me cold.

I don't want to live to see 100. The world is going to hell in a handbasket, and I'm counting on not being around when it finally gets there.

While this is hardly conclusive evidence, it is an interesting bit of information and hopefully other scientists will pursue exploring it. What I believe it SEEMS to point to is that the age of a human egg is extremely important, something that has only received attention in fairly recent times.

Another poster exclaims "ew! 50 year old moms", and it is true we are ambivalent about WOMEN having children later in life, while it has always been hunky-dory for men to father children well into senility. But until recently, the general thought was that a woman much over 45 wasn't physically up to a pregnancy. Healthy donor egg pregnancies in women as old as 67 has smashed that belief to smithereens. But the downside is that we now realize that its the egg that is the source of the limitation of female fertility -- our eggs (all present at our birth) were only designed to last about 40 years, then deteriorate.

However, I think to conclude that this possible evidence (that children concieved from young female eggs can potentially live to 100) is really telling us that the future will belong to women who FREEZE their young, super-healthy, exceptional eggs at 18 or 20 and then bank them for the future. This is technology that is right on the brink of breaking through, and it will free womankind from the current, cruel imbalance -- that men (biologically speaking) have an extra 20 years to search for the perfect partner and make a family, and women do not.

Personally, I cannot imagine anything more empowering than this knowledge and this technology. Imagine a world where there IS NO TICKING BIOLOGICAL CLOCK, where you can make life choices based on the needs and realities of your own dreams and not be leashed to a rigid, ruthless, unforgiving time deadline or end up childless.

This is good information (in the article) and it should be further explored....the ramifications for women are all positive, in my opinion and not negative and should not be interpreted as a "married at 18, barefoot and pregnant" sort of agenda.

If you've lived to be 100, that means you were born prior to 1906. Not much in the way of reproductive choice back then, women marrying young. I'd say the sheer number of babies born to women under 25 was a lot higher then. My great grandmother was married at 15 and had five children before age 25. She buried two of them in infancy.

I noticed another interesting correlation related to the age of mothers back in those days. As a child, I used to love to wander around old cemeteries and read headstones, making up stories in my mind about the people buried there. (You're right, I was definitely a weird child.) And in addition to lots of headstones for tiny babies, I noticed a lot of headstones for women who died in their teens and early twenties. When I figured out the reason for that, I become a very young advocate for reproductive rights.