Having children is bad for your health:
A pair of researchers, drawing on the experience of nearly 22,000 couples in the 19th century — has measured the “fitness cost” of human reproduction. This is the price that parents pay in their own health and longevity for the privilege of having their genes live on in future generations. The findings, published last month in the Proceedings of the National Academy of Sciences, manage to be both predictable and surprising.
Not surprisingly, women paid a bigger price than men. Older mothers were four times as likely to die in the year after having a child than their mates. Having lots of children was especially risky. A mother of 12 had five times the risk of dying prematurely as a mother of three. Even after their child-bearing years came to an end, women who had had many children died earlier than women who had had few.
The price of parenthood wasn’t trivial for men, either. Despite the obvious fact that men avoided the hazards of childbirth, fathering more children meant more risk of dying before their time, too.
Why do kids shorten our life spans? Simply put, kids are stressful, and chronic stress is toxic:
As cells age, chromosomes, where genetic information is stored, lose material from their ends, the DNA-protein structures called “telomeres.” When telomeres get too short, a cell can’t divide any more. It becomes senescent, or terminally old.
A study published in 2004 by Elissa S. Epel of the University of California at San Francisco measured telomere length in 39 mothers who were caring for children with chronic illnesses and 19 mothers raising healthy ones. She found that among the mothers of the sick children, the longer a woman had cared for her child, the shorter her telomeres. This was true even after adjusting for the telomere shortening that comes purely with age.
Between the women with the highest and lowest scores on a test of psychological stress, telomere lengths differed as much as between people 10 years apart in age.
If you want to live longer, get a pet, not a kid.
PS. Having kids also makes you unhappy, at least when your happiness is evaluated on a moment-by-moment basis. As Daniel Gilbert notes, “The only known symptom of the empty-nest syndrome is increased smiling. Careful studies of how women feel as they go about their daily activities show that they are less happy when taking care of their children than when eating, exercising, shopping, napping, or watching television.” According to the data, looking after the kids is only marginally better than mopping the floor.