By Scott Ganz

1. The V sign

Two fingers, two signs, two very different meanings. Making the v sign with the back of the hand has been a profane gesture in England for more than a century. It means, essentially, “up yours.” But during World War II, the gesture—and the meaning—got flipped around. The change started with a Belgian politician named Victor de Laveleye, who fled to England after the Nazis occupied his homeland. While living in exile, de Laveleye directed radio broadcasts for the BBC and suggested that listeners in occupied Europe use the letter V as a symbol of resistance. (In French, V stands for victoire, “victory,” and in Dutch, it stands for vrijheid, “freedom.”) De Laveleye hoped that seeing the V all across the continent would demoralize the Nazis. The British press ran with the idea, and soon, it became popular for people in Allied Europe to form the letter V with their fingers, palms turned out. In time, the V became a general sign of encouragement, and later, peace.

2. The Bird

The middle finger has been around for centuries, popping up whenever someone needed an easy way to express displeasure with his fellow man. How did it start? Flipping “the bird” actually goes back to ancient Rome, where it was called digitus impudicus, or the indecent finger. Romans thought an extended middle finger resembled a man’s reproductive organ, which supposedly warded off the evil eye. Hence, whenever Romans were met with a malicious stare, they believed they could protect themselves from being cursed by flashing their magical hand organ. Remember, these people conquered the world.

3. You're Out

Umpires have to be good at two things: soaking up verbal abuse and calling plays. But where did they get those gestures? For years, umpires didn’t talk with their hands at all. In fact, it was considered undignified to engage in such histrionics during the gentleman’s game of baseball. However, as the sport became more popular and the crowds grew bigger and louder, it became difficult to hear the umpire’s voice. In the early days of the 20th century, retired Civil War General Andrew Sheridan Burt reportedly wrote a letter to the American League and suggested that refs use hand gestures to communicate. Eventually, the League took his suggestion, and after years of experimentation, famed umpire Bill McGowan standardized the ump’s pantomime in 1925.

4. The fist bump

The so-called “terrorist fist-jab” doesn’t come from Hezbollah. Rather, it comes from pro boxers in the 1970s, after people began imitating how they touched gloves before a match. Later, the gesture became popular among basketball players, who would bump fists with their teammates instead of shaking hands, to preserve the chalk on their palms. The gesture soon spread to all basketball lovers, and, before long, to the President of the United States.

5. Thumbs up, thumbs down

You may have heard that when a Roman gladiator lost, the crowd would give a thumbs-up if they wanted him spared or a thumbs-down if they wanted him killed. But that’s all wrong.

In truth, thumbs pointing in any direction meant one thing: Kill him! Back then, the digit represented stabbing someone with a sword. If the crowd wanted a gladiator to live, they didn’t flash any hand signs at all.

Why the mix-up? Centuries later, the French and the English both developed more positive thumb signs. For instance, when British businessmen wanted to seal a deal, they would often stick up their thumbs, wet them, and press them together. Also, when the French counted on their hands, they usually started with the thumb, so the thumbs-up came to symbolize that something was No. 1, or first-class. Once the thumbs-up became a sign of a good thing, Europeans rewrote Roman history in their own image.

Coincidentally, the Chinese also give the thumbs-up when something is excellent. During World War II, Chinese civilians kept giving the thumbs-up to the Flying Tigers, a group of American pilots who flew with the Chinese Air Force to help defend China from Japanese bombers.

The Flying Tiger pilots spread the gesture to the rest of the U.S. military, and from there, the thumbs-up made its way to Roger Ebert and the Fonz.

6. Military salute

Saluting comes from the basic etiquette of removing your hat to show respect. British military conduct from the 18th century dictated that personnel remove their caps in the presence of superior officers. But as time marched on, military headgear became more cumbersome, particularly for Britain’s Coldstream Guards and their famous bear-fur hats. So the practice was shortened to simply tipping the hat without removing it. From there, it was simplified even further to the salute we know today.