The riddle is probably the oldest form of humour and originated in the desire of primitive man to show off his cleverness. Having noticed some analogy in nature, he threw his discovery into the form of a question, hoping to score off a fellow-man who failed to produce the correct answer. The Riddle of the Sphinx is merely an interrogative form of the observation made by some early Boeotian that infants crawled, men walked upright, and old men employed a stick. It is a sign of the antiquity of riddles that among the Greeks they were usually expressed in poetry, showing that they go back to a time before writing was in common use and a verse form was a useful aid to memory.

The tradition of the riddle goes back to very early times. According to one account Homer is said to have died of vexation because he could not answer a riddle asked him by the boys of Cos: ‘What we caught we left; what we did not catch we have brought.’ Another early riddle is that propounded by Samson: ‘Out of the eater came forth meat and out of the strong came forth sweetness.’ (It may be noticed that these two riddles are not actually put in the form of a question.) Dius, the historian of Phoenicia, tells us that King Solomon and Hiram, King of Syria, sent each other riddles for solution and an agreement was made that the unsuccessful competitor should pay a large sum of money to his successful rival, with the result that Hiram had to pay a large amount to Solomon until finally he gained the upper hand by calling in the help of Abdemun, one of his subjects.