The three economists behind the finding looked at 26 years of data from children and their parents. They claim that, for each sibling who joins the brood, a child will have lower cognitive abilities, more behavioral issues, and in general, worse outcomes later in life.
It seems to come down to the amount of quality time parents can spend with each child in a large family, and the potential economic strain having more kids places on them. As in, Mommy and Daddy can't spend three hours helping three different children with homework every night; you're gonna have to figure some of this out on your own. And (in our case), you may have to—gasp!—go to a college that offers you a scholarship, because putting three kids through school is going to cost a Donald Trump-size fortune!
The researchers claim these "sacrifices" may have a long-term impact on kids in large families. In fact, they discovered the so-called measure of parental investment in older kids (how often a family eats dinner together, for example) fell by 3 percentage points after a baby's birth, cognitive scores tumbled 2.8 percentage points, and kids experienced more behavioral problems. Interestingly, girls were more likely to do worse in math following a sibling's arrival, while boys were more likely to display increased behavioral high jinks.
According to the researchers, kids in larger families were also more likely to receive less education, likely due to the cost. Basically, if you believe this study, children who have multiple siblings are more likely to have less education, lower earnings, more criminal behavior, and more teenage pregnancies.
I can't deny it's harder to give each child your undivided attention when there are more to please. But I'd argue the benefits of having a larger family outweigh the detriments. Kids in large families have automatic playmates (and tutors!), and learn to master a variety of social skills out of necessity, such as sharing, compassion, empathy, selflessness, and patience.
It's worth noting researchers found a correlation between the mom's education and academic test scores and a child's likelihood of suffering cognitive setbacks after the birth of subsequent children. More highly educated, wealthier moms had kids with less instances of cognitive difficulties, which may be a factor of whether mom is forced to go back to work post-kids, or has more flexibility career-wise.
What's your take on this study?
Melissa Willets is a writer/blogger and a mom. Follow her on Twitter (@Spitupnsuburbs), where she chronicles her love of exercising and drinking coffee, but never simultaneously.