What is the origin of shaking hands when you meet someone, and also when you leave?

Answer 1

to show that you don't have any weapons
same as the Thai "wai"

Answer 2

Its a technology Romans, Greeks, and Anglo-Saxons developed first among their soldiers or fighters and like IP addresses, the internet, GPS, and many other technologies, it then found its way into the public, percolating and finally saturating the west into the forms of handshakes we are now familiar with.

It was a thing that friendly soldiers did to confirm that they had nothing to hide interms of concealed weapons or poison. In some areas the more dominant of the hand shakers would take the hand and grip the forearm too while shaking it, others preferred to shake wrists.

Another form of deference was for the dominant hand shaker to offer one arm and the less dominant one to offer both and stretch further to shake the hand.

These days a hand shake is a hand shake & the only significant difference in meaning for that handshake (at least in western parts of the world) is dependant on what you've just been doing with that hand before you saw to shake someone else's.

Answer 3

On the tv series Planet of the Apes, one guy explained that 2 cave men probably tried to grab each others hands anticipating that each other had a weapon and ended up shaking hands. Ah yes, 4 years of college but tv ends up providing the answer.

Answer 4

Something to do with the Romans/Greeks or something like that.

Originally you would have grasped your friends lower arm as part of the shake to check they were not concealing weapons. In time this reduced to just the hand as swords were not carried.

The shake as you leave is just etiquette

Answer 5

I remember reading somewhere that shaking hands was originally a way to show that you were not holding a weapon. Don't know if it's true but it does make sense.

Answer 6

It Represents The Gentlemans Agreement.

Answer 7

From my uni years and studies, I agree that it was due to weapons checking. I think going back to the Roman Empire.
--That Cheeky Lad

Answer 8

That was how ancient tribes from more hostile regions got rid of their competitors. Having built up immunity to vicious tropical diseases, they would then pass those diseases on to the surrounding tribes to decimate them and make them weak and ready for conquest.

Answer 9

If you offered your right hand to be held by the other person, it proved you couldn't be about to use a weapon against them. Obvious, really.

Answer 10

It was a sign, by uncovering and offering the 'weapon hand' that people held no malicious intent toward each other.

Answer 11

its to show you have no weapon's in your hands when you arrive, and you've nicked nothing when you leave