The best age for women to have babies is a topic sure to inspire heated debate for as long as women keep having babies -- and now the results of yet another study are bound to add fuel to the fire: According to research published in the journal of Biodemography and Social Biology, babies born to moms in their thirties are more likely to be intelligent (!). 
 
 Data was taken from the Millennium Cohort Study (which analyzes the growth of 18,000 British children for "an extended period of time") by researchers from the London School of Economics who found that children who were born to women in their thirties outperformed their peers and scored higher in cognitive testing. Researcher Alice Goisis theorizes that this may be because "first-time mothers in their 30s are, for example, likely to be more educated, have higher incomes, are more likely to be in stable relationships, have healthier lifestyles, seek prenatal care earlier, and have planned their pregnancies," as she told The Times. 
 
 Sure, all of that is true, but this study brings up an important question: How exactly do we define "intelligence" -- and aren't we more or less born with it? Of course kids who have parents with more resources to offer (i.e., good schools, tutors, even high-quality nutrition) are going to do better when it comes to school and tests. But are book learning and intelligence really the same thing? Some of the greatest minds in history came from broken homes and poverty; many of them were born when "prenatal care" was mostly the stuff of old wives' tales and superstition. The problem with studies like this one is that they take a snapshot of a child's progress in one sphere of life at a specific time and don't take into account future accomplishments or, in this case, the many different ways intelligence manifests itself. 
 
 More from The Stir: 10 Reasons Having Babies in Your 20s Rocks 
 
 So while telling women to wait until they're absolutely ready to have children -- which very well might be when they're in their thirties -- might be good advice, I personally would take the rest of these results with a hefty grain of salt. (And I'm not saying that simply because the two children I had in my 20s are honor students! Really, I'm not.) 
 
 Image via Paul Inkles/Flickr ||||| If you're in your 20s, you're probably familiar with the feeling of being bombarded by engagement and baby announcements every time you log into Facebook. Not matching pace in the rat race to couple up, settle down, and start a family? That's okay—a new study suggests it might be wise to sit tight and wait a bit before having kids. 
 
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 Researchers at the London School of Economics analyzed data from the Millennium Cohort Study, which monitors the development of 18,000 British children for an extended period of time, in order to determine the effect of a mother's age on the growth and development of her child. The golden years? Your 30s. 
 
 The study published in the journal of Biodemography and Social Biology determined that babies born to women in their thirties are more likely to be intelligent, score higher in cognitive testing and outperform those born to women in their twenties or forties. 
 
 Additionally, "First-time mothers in their 30s are, for example, likely to be more educated, have higher incomes, are more likely to be in stable relationships, have healthier lifestyles, seek prenatal care earlier and have planned their pregnancies," researcher Alice Goisis told The Times. 
 
 And while women who give birth in their forties tend to breastfeed and read to their children more, and smoke less, this age bracket is the most likely to have obese children—as women of this age were found to be less likely than younger mothers to play with their kids. ||||| Women who have children in their thirties are more likely than mothers in their twenties and forties to give birth to smarter and healthier babies, new analysis suggests. 
 
 Data from the Millennium Cohort Study, a long-running programme which tracks the development of 18,000 British children, was used to examine the impact of a mother’s age on their child. 
 
 Researchers at the London School of Economics established children born to mothers in their thirties achieved the highest cognitive scores, outperforming those children born to twenty-something-year-old mothers and just higher than mothers in their forties. 
 
 However, the research also established women who gave birth in their forties did not play with their children as much as younger women - and their offspring were more prone to suffer from obesity. 
 
 “First-time mothers in their 30s are, for example, likely to be more educated, have higher incomes, are more likely to be in stable relationships, have healthier lifestyles, seek prenatal care earlier and have planned their pregnancies,” LSE researcher Alice Goisis, told the Times. 
 
 Ms Goisis, heading up the research published in the journal Biodemography and Social Biology, also said older mothers were less likely to smoke, more likely to breastfeed and more likely to read to their children. 
 
 LSE researchers did emphasise while their study included data from a large study, the number of mothers in their forties (just 53) examined meant more research was needed. The children were examined aged five. 
 
 The average age of mothers in the UK has steadily risen from 24.5 in 1980 to 28.1 today.
– Think a mother's age at childbirth plays any role in her child's intelligence? According to data on British kids, it sure does. Using information on 18,000 children gathered over "an extended period of time," researchers from the London School of Economics say kids born to first-time moms in their 30s have better cognitive scores and "behavioral outcomes" than first-born children with mothers in their 20s, the Independent reports. "First-time mothers in their 30s are, for example, likely to be more educated, have higher incomes, are more likely to be in stable relationships, have healthier lifestyles, seek prenatal care earlier, and have planned their pregnancies," lead author Alice Goisis tells the Times of London. These kids also outperformed children whose moms were in their 40s. Published in Biodemography and Social Biology, the study also found that children born to women in their 40s are more often obese because their moms don't play with them as much. This despite the fact that moms that age typically smoke less and breastfeed their kids, Marie Claire notes. But researchers acknowledge they culled data from only 53 mothers in their 40s. There's also the question of what defines intelligence: "Of course kids who have parents with more resources to offer (i.e., good schools, tutors, even high-quality nutrition) are going to do better when it comes to school and tests. But are book learning and intelligence really the same thing?" asks Jacqueline Cote at Cafe Mom. "And I'm not saying that simply because the two children I had in my 20s are honor students! Really, I'm not." (In the US, more women are waiting until their late 30s to have kids.)