Rhyme partly seems to be enjoyed simply as a repeating pattern that is pleasant to hear. It also serves as a powerful mnemonic device, facilitating memorization. The regular use of tail rhyme helps to mark off the ends of lines, thus clarifying the metrical structure for the listener. As with other poetic techniques, poets use it to suit their own purposes; for example William Shakespeare often used a rhyming couplet to mark off the end of a scene in a play.
Evolutionary psychologist Geoffrey Miller hypothesizes that rhyme is a form of sexually selected handicap imposed on communication making poetry harder and more reliable as a signal of verbal intelligence and overall fitness.[2]