Written by Meghan Ahearn

We all grew up with sayings that were intended to frighten us into being good or convince us to eat better. Looking back, some of these childhood proverbs don’t even make much sense. (Ever hear the claim that swallowed gum stays in your stomach for seven years? Uh-huh, sure.) However, there are quite a few axioms out there that people still believe in. That’s why we decided to investigate 10 common old wives’ tales to see how they hold up under scientific scrutiny. From the moon’s affect on crime sprees to the true causes of colds, this list is sure to surprise even the most enlightened among you.

1. Sitting too close to the TV will ruin your eyes.

False: Couch potatoes around the world will feel vindicated to learn that this warning isn’t true. According to WebMD.com, the worst thing that can happen as a result of sitting too close to the screen is a nagging headache.

2. Taking a swim less than one hour after eating will give you life-threatening cramps.

False: Countless kids were scared into thinking that if they went back in the water less than 60 minutes after eating, they would cramp up and drown. But according to MayoClinic.com, it’s perfectly safe to swim after you eat a light meal or snack. The site does recommend taking a break after eating a big meal, however–not because of cramping, but due to lethargy.

3. Chocolate causes acne.

False: All those years of teenage angst weren’t caused your weakness for Hershey’s Kisses after all. The American Academy of Dermatology says acne is not caused by any specific type of food, including chocolate. The adolescent affliction is, in fact, beyond your control, since it’s linked to the levels of testosterone in your body.

4. Feed a cold, starve a fever. (Or is it starve a cold, feed a fever?)

False: According to WebMD.com, starving is never a good idea–under any condition. When you’re ill, your body requires nutrients from all the different types of food in a well-balanced diet, including fruits, vegetables, yogurt, protein and, of course, chicken soup.

5. Carrots improve your eyesight.

Partially True: The American Optometric Association found that 48% of Americans still believe carrots are the best food for eye health. And though the root vegetable does have beta-carotene and Vitamin A, which are good for night vision, even healthier for the eyes are dark leafy greens like spinach, which contain lutein and zeaxanthin. Popeye was on to something, after all.

6. Cracking knuckles causes arthritis.

False: Here’s another parental fear tactic that isn’t all it’s cracked up to be. John H. Klippel, MD, Arthritis Foundation President and CEO, recently told USAToday.com that he doesn’t “know of any evidence that suggests that cracking one’s knuckles actually can cause arthritis.”

7. An apple a day keeps the doctor away.

Partially True: This saying has been around since before the discovery of an apple’s vital nutrients: Vitamin C and polyphenols. Regardless, the core of the matter is that while this fruit will help keep you well, it’s not always enough to keep you out of the medical danger zone.

8. Lightning never strikes the same place twice.

False: According to the National Weather Service, lightning can strike the same place numerous times. In fact, the Empire State Building is hit an average of 25 times a year–the reason why it was once used as a lightning laboratory.

9. Going out in the cold with wet hair causes sickness.

False: Neither wet nor dry hair significantly increases your chances of getting sick. WebMD.com says colds are solely caused when viruses are passed from one person to another, so you should be more concerned with how often you wash your hands, not your hair.

10. More crime occurs during a full moon.

False: Many interesting things are thought to increase during a full moon: emergency room visits, accidents, fertility, werewolves. Almost all these phenomena are attributed to the Lunar Effect, which tries to link deviant behavior and the phases of the moon. However, according to myth-buster and syndicated columnist, Cecil Adams, there is no truth at all behind the theory.