“One question I am often asked is whether these results are suggesting that women should wait to have children so they will have smarter children, and the answer is that our results are not addressing that,” Dr. Goisis said. “These women tend to be advantaged,” she said, and to take better care of themselves during pregnancy; they were less likely to smoke and more likely to breast-feed, compared to the younger mothers.

“Nowadays children of older mothers have, on average, better outcomes because of the characteristics of women who tend to have children at older ages,” Dr. Goisis said.

Other researchers have looked at the question of how parenting attitudes and practices change as mothers grow older. In a study published online in December, researchers looked at how parenting practices and children’s development varied with maternal age in a group of 4,741 families in Denmark. Older mothers were less likely to be harsh with their 7- and 11-year-old children, either in terms of scolding or of physical discipline, they found, and their children were less likely to have behavioral, social and emotional problems.

“Older mothers seem to thrive better,” said Tea Trillingsgaard, an associate professor of psychology at Aarhus University in Denmark, who was the lead author on the study. “The mothers have more psychological flexibility, more cognitive flexibility, more ability to tolerate complex emotional stimuli from the children.”

Again, the researchers looked to see whether these differences were explained by another factor, by educational level or socioeconomic status, but even after controlling for all the demographic and socioeconomic factors they had, they still found that older maternal age itself continued to be associated with these more positive outcomes. “Emotional well-being tends to increase with age,” Dr. Trillingsgaard said. “Age in itself may be an advantage.”

We all know that fertility issues increase with older childbearing, with a large and complex fertility industry growing up in part to meet the needs of women who may have more difficulty conceiving later in life. But since having children is for most of us a huge and complicated decision, involving relationships, socioeconomic factors, geography, and the whole package of individual factors roughly summed up as life, love and the pursuit of happiness, decision making often doesn’t allow for simple planning where you target one age or another.

The clear message is that the children of women with more support and better health habits do better cognitively, so it’s important to support mothers of any age. What you learn as you grow up, intellectually and emotionally, may help you in the complicated job of taking care of your own children. And after all, growing up and helping people grow up is what this is all about.