The handshake is thought to have originated as a symbol of peace
by demonstrating that neither "shaker" had a weapon in their
hand. If two men met and displayed empty right hands, this
presumably meant a basic level of trust existed and that neither
would stab the other. Of course, this explanation, doesn’t
account for left-handed men, who presumably would have been
happy to extend the right hand in greeting while wielding a
dagger in the left! In variations of this story, it is said that
the handshake evolved from an elbow-to-wrist “patdown” to check
for hidden knives; in another, the shaking motion was supposed
to dislodge any sharp objects that may have been kept in the
sleeve. Archaeological ruins and ancient texts show that
handshaking was practiced in ancient Greece from as far back as
the 5th century BC, with a depiction of two soldiers apparently
shaking hands found on part of a 5th century BC funerary stele
which is on display in Berlin’s Pergamon Museum. Another
funerary stele of the 4th century BC