Parents with more children are less likely to live long, healthy lives than those with smaller families, according to a recent study by U researchers.
The study examined the mortality of more than 21,000 married couples and their 174,000 children in Utah between 1860 and 1895, coming to the conclusion that having more children greatly reduces the chance of parental survival.
This increased mortality rate, caused by health, mental and economic factors, was especially evident in mothers. The study also concluded that children born into larger families had a lesser rate of survival.
Ken Smith of the U’s family and consumer studies department worked on this project with Dustin Penn at the Konrad Lorenz Institute for Ethology in Vienna, Austria.
By looking at a population where modern contraceptives were non-existent, Smith said they were able to look at “fertility without the ability to control it.”
This view led Smith and Penn to view menopause as an evolutionary trait to curb a woman’s ability to reproduce at a certain age and therefore preserve or prolong her health.
“The larger scientific question is, ‘Why is it that women experience menopause when most other species’ lives end after reproduction?'” Smith said. “It is unique that humans have a long life after reproduction.”
Smith called menopause a “better evolutionary strategy,” saying that through menopause women can devote their later years to raising and rearing children already born instead of continuing to reproduce.
According to the study, puberty and menopause help create an optimum time period for women to have a certain number of children and keep mothers alive.
Although the study only examined couples and children from the late 1800s, Smith said there are modern implications.
“It is still the case that couples reproduce in a fashion that could cause complications, by having children too close together, too young or by delaying childbearing into advanced years,” Smith said.
David Clark, a freshman biology and pre-dentistry major, said, “I noticed this issue more in my dad. Family stress, work stress and having to support a family really affected his health, causing him to get cancer.” His father has been in remission for almost two years.
Clark continued to say that his aunt, who has six children, developed four kinds of cancers while her children were growing up. When the children were out of the house, Clark said all of the cancers were gone, making her one of the longest survivors of those cancers.
Freshman civil engineering major Austin Orr said that he has four full siblings and 12 half- and stepsiblings. “All of my parents are in good health,” Orr said.
Smith said that the average Utah family has about 2.8 children, almost one child more than the national average of 2.1.
“A difference in one makes a big difference,” Smith said.