CLOSE
Original image

Happy birthday to them!

Original image

As you might know, tomorrow is February 12th. It's also the 199th anniversary of Charles Darwin's birth. It's also the 149th anniversary of the publication of Darwin's "The Origin of Species." It's also the 199th anniversary of Abraham Lincoln's birth.

So many things to celebrate tomorrow; where to start?

How about we just concentrate on the wonderful coincidence that Darwin and Lincoln share the same birthday AND year!

I share a birthday with my mother, Bruce Lee and Jimi Hendrix. Not the same year, obviously, just the same day. Every time I go out to a restaurant to celebrate my birthday, it seems someone else is there doing the same thing, stealing my thunder, and often my piece of free birthday cake. An actuary friend explained that if you got 23 people together in a room, there's a 50-50 chance of at least one coincidental birthday.

After the jump, you'll find a complete breakdown for those who are curious to see the math involved. But first, with whom do you share a birthday? We'd love to know, especially if it's the same day AND year.

To figure out the exact probability of finding two people with the same birthday in a given group, it turns out to be easier to ask the opposite question: what is the probability that NO two will share a birthday, i.e., that they will all have different birthdays? With just two people, the probability that they have different birthdays is 364/365, or about .997. If a third person joins them, the probability that this new person has a different birthday from those two (i.e., the probability that all three will have different birthdays) is (364/365) x (363/365), about .992. With a fourth person, the probability that all four have different birthdays is (364/365) x (363/365) x (362/365), which comes out at around .983. And so on. The answers to these multiplications get steadily smaller. When a twenty-third person enters the room, the final fraction that you multiply by is 343/365, and the answer you get drops below .5 for the first time, being approximately .493. This is the probability that all 23 people have a different birthday. So, the probability that at least two people share a birthday is 1 - .493 = .507, just greater than 1/2.

Statistics courtesy of Math Guy over at NPR.

Original image
iStock
arrow
Animals
25 Benefits of Adopting a Rescue Dog
Original image
iStock

According to the ASPCA, 3.3 million dogs enter shelters each year in the United States. Although that number has gone down since 2011 (from 3.9 million) there are still millions of dogs waiting in shelters for a forever home. October is Adopt a Shelter Dog Month; here are 25 benefits of adopting a shelter dog.

Original image
iStock
arrow
fun
How Urban Legends Like 'The Licked Hand' Are Born
Original image
iStock

If you compare the scary stories you heard as a kid with those of your friends—even those who grew up across the country from you—you’ll probably hear some familiar tales. Maybe you tried to summon Bloody Mary by chanting her name in front of the mirror three times in a dark bathroom. Maybe you learned never to wonder what’s under a woman’s neck ribbon. Maybe you heard the one about the girl who feels her dog lick her hand in the middle of the night, only to wake up to find him hanging dead from the shower nozzle, the words “humans can lick too” written on the wall in the dog’s blood.

These ubiquitous, spooky folk tales exist everywhere, and a lot of them take surprisingly similar forms. How does a single story like the one often called “Humans Can Lick Too” or "The Licked Hand" make its way into every slumber party in America? Thrillist recently investigated the question with a few experts, finding that most of these stories have very deep roots.

In the case of The Licked Hand, its origins go back more than a century. In the 1990s, Snopes found that a similar motif dates back to an Englishman’s diary entry from 1871. In it, the diary keeper, Dearman Birchall, retold a story he heard at a party of a man whose wife woke him up in the middle of the night, urging him to go investigate what sounded like burglars in their home. He told his wife that it was only the dog, reaching out his hand. He felt the dog lick his hand … but in the morning, all his valuables were gone: He had clearly been robbed.

A similar theme shows up in the short story “The Diary of Mr. Poynter,” published in 1919 by M.R. James. In it, a character dozes off in an armchair, and thinks that he is petting his dog. It turns out, it’s some kind of hairy human figure that he flees from. The story seems to have evolved from there into its presently popular form, picking up steam in the 1960s. As with any folk tale, its exact form changes depending on the teller: sometimes the main character is an old lady, other times it’s a young girl.

You’ll probably hear these stories in the context of happening to a “friend of a friend,” making you more likely to believe the tale. It practically happened to someone you know! Kind of! The setting, too, is probably somewhere nearby. It might be in your neighborhood, or down by the local railroad tracks.

Thrillist spoke to Dr. Joseph Stubbersfield, a researcher in the UK who studies urban legends, who says the kind of stories that spread widely contain both social information and emotional resonance. Meaning they contain a message—you never know who’s lurking in your house—and are evocative.

If something is super scary or gross, you want to share it. Stories tend to warn against something: A study of English-language urban legends circulating online found that most warned listeners about the hazards of life (poisonous plants, dangerous animals, dangerous humans) rather than any kind of opportunities. We like to warn each other of the dangers that could be lurking around every corner, which makes sense considering our proven propensity to focus on and learn from negative information. And yes, that means telling each other to watch out for who’s licking our hands in the middle of the night.

Just something to keep in mind as you eagerly await Jezebel’s annual scary story contest.

[h/t Thrillist]

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios