5 Takeaways From the Study That Found Second-Born Boys Get Into More Trouble

iStock
iStock

Researchers have tried to understand how siblings' birth order affects their competitiveness, intelligence, kindness and other personality traits for more than a century. Now, a new study [PDF] backs up what plenty of older siblings have long argued: their younger brothers are more prone to get in trouble. Here are five takeaways from the thought-provoking research.

1. SECOND-BORN SIBLINGS ARE MORE LIKELY TO GET IN SERIOUS TROUBLE.

The study focused mostly on older brother/young brother and older sister/younger brother sets of siblings. Among two brothers, the younger boys were found to be 20 to 40 percent more likely to be disciplined in school or get in trouble with the law compared to the older boys. As study co-author Joseph Doyle, an economist at MIT, told NPR, "I find the results to be remarkable that the second-born children, compared to their older siblings, are much more likely to end up in prison, much more likely to get suspended in school."

2. THE EFFECT WAS MORE PRONOUNCED FOR BOYS.

Doyle and his colleagues didn't find the same trend among second-born girls with older brothers or sisters. Boys and girls have different rates of delinquency; in this study, the average number of delinquent first-born girls in sister pairs was 54 to almost 100 percent lower than first-born boys in brother pairs. "The gaps in delinquency are smaller when we investigate the effect of being a second-born girl," they write.

3. THE RESULTS WERE SIMILAR IN DIFFERENT ENVIRONMENTS.

The researchers used birth registries in Denmark and in Florida that identified siblings so birth order could be determined. Then, they compared that data to school records, criminal databases, and medical or public health records. Despite differences in racial demographics, education levels, parental employment, and approaches to crime and punishment between the two locales, the researchers found that "second-born boys are substantially more likely to exhibit delinquency problems compared to older siblings" in both Denmark and Florida.

4. FAMILY DYNAMICS PROBABLY PLAY A PART.

Among the families studied, first-born and second-born siblings were equally healthy and achieved similar levels of education, so those factors did not play a large part in explaining the younger kids' propensity for trouble. Instead, the researchers suggest there is less maternal attention paid to second-born children. First-born children "experience their mothers' maternity leaves … both following their own births as well as following the births of the second-born." In other words, Jan Brady might have been right about her sister Marcia.

5. OTHER STUDIES HAVEN'T UNCOVERED THE SAME LINK.

Previous studies have found little connection between certain personality traits or intelligence and the order in which siblings were born. A 2013 paper suggested that "contrary to popular belief, the relationship between birth order and delinquency is spurious." When it comes to interpreting the effects of birth order, researchers are still—metaphorically, at least—fighting over the TV remote.

Take Advantage of Amazon's Early Black Friday Deals on Tech, Kitchen Appliances, and More

Amazon
Amazon

This article contains affiliate links to products selected by our editors. Mental Floss may receive a commission for purchases made through these links.

Even though Black Friday is still a few days away, Amazon is offering early deals on kitchen appliances, tech, video games, and plenty more. We will keep updating this page as sales come in, but for now, here are the best Amazon Black Friday sales to check out.

Kitchen

Instant Pot/Amazon

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- Anova Culinary Sous Vide Precision Cooker; $139 (save $60)

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- Longzon Silicone Stretch Lids - Set of 14; $13 (save $14)

HadinEEon Milk Frother; $37 (save $33)

Home Appliances

Roomba/Amazon

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Vitamix 068051 FoodCycler 2 Liter Capacity; $300 (save $100)

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Video games

Sony

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BioShock: The Collection; $20 (save $30)

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Luigi's Mansion 3 for Nintendo Switch; $40 (save $20)

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Microsoft/Amazon

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Apple iPad Mini (64 GB); $379 (save $20)

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Tech, gadgets, and TVs

Apple/Amazon

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Canon EOS M50 Mirrorless Camera with EF-M 15-45mm Lens; $549 (save $100)

DR. J Professional HI-04 Mini Projector; $93 (save $37)

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The Great Tryptophan Lie: Eating Turkey Does Not Make You Tired

H. Armstrong Roberts/iStock via Getty Images
H. Armstrong Roberts/iStock via Getty Images

While you’re battling your kids for the best napping spot after Thanksgiving dinner, feel free to use this as a diversion tactic: It’s a myth that eating turkey makes you tired.

It’s true that turkey contains L-Tryptophan, an amino acid involved in sleep. Your body uses it to produce a B vitamin called niacin, which generates the neurotransmitter serotonin, which yields the hormone melatonin, which helps regulate your sleeping patterns. However, plenty of other common foods contain comparable levels of tryptophan, including other poultry, meat, cheese, yogurt, fish, and eggs.

Furthermore, in order for tryptophan to produce serotonin in your brain, it first has to make it across the blood-brain barrier, which many other amino acids are also trying to do. To give tryptophan a leg up in the competition, it needs the help of carbohydrates. Registered dietitian Elizabeth Somer told WebMD that the best way to boost serotonin is to eat a small, all-carbohydrate snack a little while after you’ve eaten something that contains tryptophan, and the carbs will help ferry the tryptophan from your bloodstream to your brain.

But Thanksgiving isn’t exactly about eating small, well-timed snacks. It’s more about heaps of mashed potatoes, mountains of stuffing, and generous globs of gravy—and that, along with alcohol, is more likely the reason you collapse into a spectacular food coma after your meal. Overeating (especially of foods high in fat) means your body has to work extra hard to digest everything. To get the job done, it redirects blood to the digestive system, leaving little energy for anything else. And since alcohol is a central nervous system depressant, it also slows down your brain and other organs.

In short, you can still hold turkey responsible for your Thanksgiving exhaustion, but you should make sure it knows it can share the blame with the mac and cheese, spiked apple cider, and that second piece of pumpkin pie.

[h/t WebMD]