Though it may feel like a way to assert your dominance when you squeeze the other hand as hard as possible, it actually originated from a very peaceful gesture in a tumultuous time.
The first time a handshake was documented appears on the Kalhu monument, which shows the Assyrian king, Shalmaneser III, and Babylonian Marduk-zakir-sumi, shaking hands in public to show friendship between the nations.
It's believed to be practiced all the way back to the 5th century BC in ancient Greece. Archeologists have found pottery with soldiers shaking hands in many of the ruins.
The thought behind the handshake was as a gesture of peace and trust. A soldier would present a hand that doesn't have a weapon.
Today, handshakes mean many things other than an almost universal greeting. They now convey anything from congratulations, to respect, to a binding agreement.
