Children with older parents may have a surprising leg up
Delaying starting a family by a year is associated with a 9% increase in a woman's earnings over the course of her career; that increase adds up for every extra year she waits.
Besides that benefit for women, waiting longer to start having kids is also linked to some good things for the kids themselves.
Amalia Miller, an economist at the University of Virginia, looked at test scores in reading and math for over 1,000 students and found that a year's delay in a woman starting a family was associated with a small but significant increase in her child's test scores, on average. "A 7 year delay," Miller notes in the paper, "produces gains on par with the black-white score difference" - a major and much-studied disparity.
Now, this doesn't mean that children born to older mothers always scored better on the tests than those with younger mothers, and in her paper Miller notes that "motherhood timing is clearly not the main source of test score differences."
Still, in analyzing the data (pulled from a national survey conducted by the Bureau of Labor Statistics), Miller found that the increase in test scores she saw held even when she controlled for financial status, family structure, race, and level of education. She also factored in how long it took women to get pregnant, whether they had used contraception, and whether they'd had any miscarriages. That helped Miller gauge the effect of unintentional delay, to try to rule out the possibility that women's personal traits or situations were the driving force behind when they decided to have kids and what those kids' test scores were.
But whether women had waited by design or by chance, the higher test scores for kids with mothers who delayed starting a family remained.
So, what's the reason?
She notes that more research is necessary to provide evidence supporting that hypothesis, but Miller isn't the only one to posit that older women make better parents.
Lois Nachamie, a board certified psychotherapist in private practice in New York City who specializes in parenting issues, told Business Insider that in her experience, older women are generally more emotionally ready to be mothers than younger women are. (There's some research supporting this view.)
Parents have to put the needs of their child above their own, and this can be harder for a younger person who is, appropriately for her age, focused on her own career, growth, fun, and intellectual development, Nachamie told Business Insider. With age, people develop to the point where they're more willing and able to meet the needs of another, in general.
"By the time you're in your 30s, you have a fair amount of accomplishment under your belt, which I think gives you a little bit more ability to not necessarily resent the neediness of an infant and a toddler," Nachamie said.
Whether or not the difference in older and younger parents Nachamie pointed out is related to the trend in test scores Miller observed, as more women wait longer to have kids, the consequences for individual families and society are significant, changing our society in ways we may not expect.