Handshake
Shaking with the right hand while delivering a certificate with the left
A handshake is a short ritual, where both right or left hands briefly grasp each other, usually done when two people meet or depart, or complete an agreement. Its purpose is to demonstrate good will, and it has possibly originated as a gesture to show that the hand holds no weapons. On cattle markets, one can sometimes see cattlefarmers slapping hands while negotiating a deal. One will name a price and slap the others hand. If the other one does not like the price, he will slap the others hand and name his price. This will go on until one shakes the others hand instead of slapping it, thus concluding the deal.
Generally it is considered inappropriate to reject a handshake, and in most social circles it is expected that the one with higher social status will initiate it. To offer the left hand instead of the right was once considered an insult. In some societies, mostly Arabic or oriental, this is still the case. There the left hand is considered unclean, since this hand is used to clean one's behind with water after defecating. Boy scouts specifically use a left handshake. The left hand normally holds a shield. By shaking with the left hand, one is defenseless while trusting the other person who may still be holding a weapon in the right hand. [1]
Handshake is originally a Western European tradition, brought into practice in its present form by English Quakers in 17th century as a more egalitarian and simpler alternative to the complex greeting etiquette of the contemporary higher social classes. Today handshake is known and practiced throughout the world, though in many cultures alternative customs for greeting, such as bowing or cheek kissing are still preferred.
Handshakes are a major route for the transmission of common cold viruses.