When two or more people feel the sudden need to celebrate, perhaps after a scored point or an exciting announcement, they may engage in a celebratory gesture known as a high five. A high five involves one person holding his or her hand high in the air and allowing another person to slap it with his or her own. The "high" in a high five refers to the height of the slap, and the "five" means the five fingers used by each slapper. Sometimes the action of a high five is a mutual hand slap, but it may also be a less ostentatious meeting of open palms. Whatever the energy level of a high five, the important thing is that both participants agree it's about to happen.
A high five may be followed by any number of other gestures or rehearsed routines. Some people may interlock their fingers in a further show of solidarity. Others follow up a traditional high five slap with a windmill gesture ending in a second and much lower slap known as a low five. It's even possible that two participants will deliberately miss the high five signal altogether to perform a low five instead. There is also the dreaded maneuver where a potential high fiver is left hanging in mid-air when the other side suddenly balks.
There is a surprising amount of debate over the origins of the high five, although most sources agree that it most likely came from the world of sports. Some believe the high five was first seen on a public scale during a baseball game in which two fielders congratulated each other with a high hand slap. Others suggest it was first used by basketball players who used their height advantage to slap their hands together over the heads of their opponents. Some say a high five gesture didn't become popular until the 1970s, but others say rudimentary forms of a high hand slap can be seen on 1950s era television shows.
The high five gesture has waxed and waned in popularity over the years, often replaced with more elaborate hand-slapping routines or other forms of contact such as fists, chests or forearms. Some sports team members routinely celebrate points with high five gestures, most notably volleyball and basketball players. It is also interesting to note that the third Thursday in April has been officially recognized as National High Five Day by the United States government.