10 Times Correlation Was Not Causation

Katie Carey
Katie Carey

It’s a scientist’s mantra: Correlation does not imply causation. But sometimes wrong feels so right.

1. EAT ENOUGH CHOCOLATE AND YOU'LL WIN A NOBEL.

If you want to boost blood flow to your brain and (potentially) slow cognitive decay, consume flavanols. The plant compounds, found in green tea and cocoa, are great for getting blood into your noggin. That made New York doctor Franz Messerli wonder: Would a nation of bonbon–eaters be more intellectually accomplished than a country that didn’t consume as much cocoa? In a tongue-in-cheek 2012 paper published in The New England Journal of Medicine, he found that countries that ate a lot of chocolate also won the most Nobel Prizes. Messerli published the study with a wink, but some media outlets took the news seriously, failing to see that a confounding variable was at play—wealth. A richer country (like Switzerland, which has 26 Nobel winners) will have more quality scientific research—and well-stocked shelves of chocolate, too.

2. THE NIGHT-LIGHT BIZ IS IN CAHOOTS WITH YOUR OPTHALMOLOGIST.

Nearsightedness has been increasing worldwide for decades. In some Asian countries, up to 90 percent of adults can’t see distant objects clearly, and in 1999, researchers at the Children’s Hospital of Philadelphia thought they’d found the cause: night-lights. The evidence suggested that kids who slept with a light developed myopia later in life. But two groups of researchers argued that the study failed to see the evidence in front of its nose—myopic parents have myopic kids. And myopic parents, who can’t see well in the dark, are more likely to install night-lights in their children’s rooms.

3. BLACK CATS ARE SO UNLUCKY, THEY'LL GIVE YOU ALLERGIES.

Are black cats bad luck for your sinuses? In a January 2000 paper for the Journal of Allergy and Clinical Immunology, researchers found that people with dark-colored cats suffered more allergic reactions than owners of light-colored cats (or no kitty at all). But the correlation appears to have just been a coincidence. Cat allergies are actually caused by a protein called Fel d 1, which is produced in salivary and sebaceous glands. A research team in New Zealand found that cat allergies simply aren’t related to cat color or hair length.

4. FORGET ABOUT APPLES: HEAD LICE KEEPS THE DOCTOR AWAY.

For centuries, natives of the New Hebrides islands considered a head full of lice a sign of good health. “Observation over the centuries had taught them that people in good health usually had lice and sick people very often did not. The observation itself was accurate and sound,” writes Darrell Huff in How to Lie with Statistics. But the correlation didn’t mean lice are the key to good health—it’s the other way around. Healthy people had lice because their body was just the right temperature, a perfect home for bugs. But when people ran a high fever, their flesh became hot, sending the lice scattering. Lice didn’t cause good health—they preyed on it.

5. SERVING BREAKFAST WILL BOOST YOUR CHILD'S REPORT CARD.

We’ve all heard that kids who eat breakfast do better in school. It makes sense; it’s hard to focus on an empty stomach. But despite their best attempts, researchers haven’t been able to pinpoint why breakfast aids learning—if that’s even the case. A 1996 study of Jamaican students found that, in some schools, kids behaved better after they ate breakfast; in other schools, they acted worse. The gap probably had more to do with each school’s resources than with a student’s daily ration of Cocoa Puffs. Students at well-equipped schools behave better regardless of their diet.

6. STORKS AND BABIES ARE INEXTRICABLY INTERTWINED.

Storks do not deliver babies. That bit of German folklore likely originated because the white stork’s migration rituals last nine months. (Plus, Hans Christian Andersen helped popularize the myth in his short story “The Storks.”) But that hasn’t stopped scientists from acknowledging a striking correlation: Between 1970 and 1985, the number of breeding pairs of white storks in Lower Saxony dropped. Over the same period, the birth rate there also fell. Meanwhile, stork numbers increased in Berlin’s suburbs, where doctors delivered more babies. As Robert Matthews writes in Teaching Statistics, “While storks may not deliver babies, unthinking interpretation of correlation ... can certainly deliver unreliable conclusions.”

7. IF YOU'RE A DIEHARD FAN, LOSING THE SUPER BOWL WILL LITERALLY KILL YOU.

Hours after the Seattle Seahawks lost the Super Bowl in 2015, fan Michael Sven Vedvik died. In his obituary, his family blamed the team’s “lousy play call for Mike’s untimely demise.” The joke echoed 2011 research in Clinical Cardiology linking Super Bowl losses to a 15 to 27 percent increase in cardiac deaths in the loser’s hometown. (The Grim Reaper has tried wearing cleats at least once: When the Steelers’ Jerome Bettis fumbled in a 2006 playoff game, a fan watching from a bar became so upset that he had a heart attack. Fortunately, he survived.) Problem is, the studies don’t take non-football variables into account. And the data in one study investigated deaths that occurred two weeks after the game. “I don’t think that everyone who dies within 14 days of the Super Bowl died because of the Super Bowl,” David Prince of Albert Einstein College of Medicine told Live Science.

8. EMPLOYED? THANK YOUR OVERPRICED GROCERY STORE.

In 1958, economist William Phillips published a paper claiming that when unemployment increased, inflation decreased (and vice versa). “That led nations to start thinking of these two variables as trade-offs,” says Rebecca Goldin, professor of math at George Mason University and director of the website Sense About Statistics. “Some would focus on unemployment while others focused on controlling inflation, but they all saw this as a causal trade-off.” Then came the 1970s, when many countries saw both high inflation and high unemployment. Turns out Phillips’s “rule” was just a short-term coincidence. While inflation can affect unemployment for short periods, it can’t fix joblessness over the long run.

9. LONELY PEOPLE KEEP THE SPA INDUSTRY ROLLING IN THE DOUGH.

In Scandinavia, people fight the cold of winter with cozy candlelit social gatherings. Called hygge in Denmark and koselig in Norway, the tradition suggests there’s a connection between physical temperature and the “social warmth” of friends. In 2011, Yale researchers suggested that people may instinctively reach for that connection in the shower. In a study, they found that lonely people were more likely to take long, warm showers and baths. Was it because higher temperatures make them feel less isolated? Well, the methodology left critics cold. The study used a small sample (only 51 undergrads); of those, 90 percent reported bathing or showering less than once a week. Not exactly a trusty sample. In 2014, a different team tried to replicate the results using a larger (and presumably better-smelling) group, and failed.

10. THE POPE SHOULD PRAY FOR THE WELSH RUGBY TEAM... TO LOSE.

According to the 2008 study “Rugby (the Religion of Wales) and its Influence on the Catholic Church,” the Pope is more likely to die when the Welsh rugby team wins the sport’s Grand Slam. The paper—which appeared in the British Medical Journal’s humorous annual Christmas issue—found no connection between the pontiff’s mortality and teams from other countries. Just Wales. We expect a Dan Brown book about this any time now.

Turn Your LEGO Bricks Into a Drone With the Flybrix Drone Kit

Flyxbrix/FatBrain
Flyxbrix/FatBrain

Now more than ever, it’s important to have a good hobby. Of course, a lot of people—maybe even you—have been obsessed with learning TikTok dances and baking sourdough bread for the last few months, but those hobbies can wear out their welcome pretty fast. So if you or someone you love is looking for something that’s a little more intellectually stimulating, you need to check out the Flybrix LEGO drone kit from Fat Brain Toys.

What is a Flybrix LEGO Drone Kit?

The Flybrix drone kit lets you build your own drones out of LEGO bricks and fly them around your house using your smartphone as a remote control (via Bluetooth). The kit itself comes with absolutely everything you need to start flying almost immediately, including a bag of 56-plus LEGO bricks, a LEGO figure pilot, eight quick-connect motors, eight propellers, a propeller wrench, a pre-programmed Flybrix flight board PCB, a USB data cord, a LiPo battery, and a USB LiPo battery charger. All you’ll have to do is download the Flybrix Configuration Software, the Bluetooth Flight Control App, and access online instructions and tutorials.

Experiment with your own designs.

The Flybrix LEGO drone kit is specifically designed to promote exploration and experimentation. All the components are tough and can totally withstand a few crash landings, so you can build and rebuild your own drones until you come up with the perfect design. Then you can do it all again. Try different motor arrangements, add your own LEGO bricks, experiment with different shapes—this kit is a wannabe engineer’s dream.

For the more advanced STEM learners out there, Flybrix lets you experiment with coding and block-based coding. It uses an arduino-based hackable circuit board, and the Flybrix app has advanced features that let you try your hand at software design.

Who is the Flybrix LEGO Drone Kit for?

Flybrix is a really fun way to introduce a number of core STEM concepts, which makes it ideal for kids—and technically, that’s who it was designed for. But because engineering and coding can get a little complicated, the recommended age for independent experimentation is 13 and up. However, kids younger than 13 can certainly work on Flybrix drones with the help of their parents. In fact, it actually makes a fantastic family hobby.

Ready to start building your own LEGO drones? Click here to order your Flybrix kit today for $198.

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How to Brew Your Own Fluorescent Beer at Home

The Odin
The Odin

If you're one of the many people who made their own sourdough starter in quarantine, you already know yeast is a living thing. That means its biological makeup can be tweaked using genetic engineering. As Gizmodo reports, that's exactly what a former NASA biologist has done to create his new fluorescent yeast kits.

A few years ago, Josiah Zayner left his job as a synthetic biologist for NASA to found The Odin, a company that lets anyone experiment with genetic science at home. His recently launched yeast kit accomplishes this in an eye-catching way. Thanks to a fluorescent protein from jellyfish, yeast that's been genetically modified with the kit glows green under a black or blue light.

Despite looking like a prop from a sci-fi film, the yeast is still yeast. That means it can be used in home-brewing projects if you want to take the science experiment a step further. According to Eater, yeast made with the kit ferments and fluoresces when added to honey and water. If you brew a batch of beer with the right amount of yeast, the final product will emit an otherworldly glow when viewed under a blacklight. The kit hasn't been FDA approved, but the company states the materials are nontoxic and nonallergenic, and beer made with it will still taste like beer.

You can purchase a fluorescent yeast kit from The Odin's online shop for $169. If you're looking for more ways to experiment with genetic technology at home, the company also sells kits that let you play with frog and bacteria DNA.

[h/t Gizmodo]