Posted on 05/10/2002 5:59:36 AM PDT by Cagey
WASHINGTON (Reuters) - Mothers who have complained through the centuries that their sons will be the death of them may be right -- a Finnish study published on Thursday shows having boys shortens a woman's life span.
Each son takes an average of 34 weeks off a woman's life span, evolutionary biologist Samuli Helle and colleagues at the University of Turku found.
On the other hand, having daughters adds, but only very slightly, to a woman's life span, said the report in Friday's issue of the journal Science.
Helle, a Ph.D student at the university, was trying to prove having large families can cause women to die early. But his study of church records among the Sami people of northern Scandinavia found that family size could not predict reliably that a woman would die young.
"We found that maternal longevity was not related to the total number of children born or raised to adulthood, suggesting that large families were raised by wealthy individuals," the researchers wrote in their report.
"That's a bit surprising ... because theory predicts there should be a negative effect," Helle said in a telephone interview.
"But I think, in our case because we have no data about individual wealth, it would be that those with the highest status and wealth could afford both to have many children and had a long life span."
Helle and colleagues looked at birth and marriage records of Sami people from 1640 to 1870. "These Sami depended mainly on reindeer herding, fishing and hunting for their livelihood and experienced natural mortality because of a lack of advanced medical care," they wrote.
They only looked at women who lived to be over 50, and took into account whether a woman's husband had died, since raising a family alone would be stressful.
"Our results suggest that giving birth to sons had a higher relative long-term survival cost for mothers than giving birth to and raising daughters," they wrote.
There could be biological reasons for this. Studies show boys are physiologically more demanding to produce -- they grow bigger and faster in the womb, and some studies show it takes a woman longer to get pregnant again after having a son than after having a daughter.
Testosterone produced by the fetus could suppress the mother's immune system and perhaps make her more susceptible to disease, Helle's team wrote, citing recent studies that have shown that.
There could be genetic or social differences among the Sami, who are distinct from their Finnish and Swedish neighbors, Helle said. But he does not think so.
"There is no reason to believe that this effect would be only visible in Sami people," he said.
He thinks it could be simple behavior. "Generally, boys get on their mothers' nerves more than girls because they are running around, and girls are more willing to help their mothers," he said
Insomnia comes to mind.
I'm glad he started the study with an open mind
Well, except for the early years, large families tend to do economically better than smaller families because -- ta da -- there are more productive workers in large families than in small families. They can more likely weather income disruptions, sicknesses, etc -- since they can draw on each other in times of personal need.
That's why even in the poorest countries, people strive to have big families.
So he is basis his arguement on data that is over 140 years old. Seems to me that it may have been so then but with technology and social advances since then you can't really extrapolate this far into the present from that far in the past.
The question now should be, "Have the results changed as we (society) try to change boys into acting like girls and now have girls acting more like boys?"
In any event, without boys (and girls) there will be no more people at all. I think that 34 weeks is a small price to pay for ensuring the viability of the species.
God Save America (Please)
I don't think it has ANYTHING to do with situations when the kids are younger. I believe it has to do with the amount of attention given by the boys to their mothers as they age. My mother's favorite comment was "A son is a son til he takes a wife, a daughter is a daughter all of her life." It is a statment of reality that a son will turn his attentions to his own wife and family (as it should be), but a daughter will continue to be solicitous to her mom. My mom was thrilled that we had at least one daughter to go with our 3 sons. As mothers age, things that they need done will more likely be done by their daughters than their sons, as least it has been that way in our family's experience. I'm sure there are many sons who are very cognizant of their mothers' needs, but I think it is the daughters who do the most in this regard.
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