Shots are a drinking tradition the world over. Before all these fancy mixed cocktails were invented most people took shots of straight booze. Depending on where you lived in the world it was either Vodka, Rum, Whiskey, Tequila or Brandy.
Many countries also have a special liqueur that is used to toast friends and loved ones on special occasions.
Most of these are not born of ancient tradition, rather they came from generations of college and holiday parties.