What part has sexual choice played in the evolution of our brains? Quentin Cooper talks to evolutionary psychologist Geoffrey Miller who argues that the human mind, like the peacock's tail, has evolved primarily for courtship and mating. An ability to tell jokes might not help us avoid a predator, but it makes us a more attractive mate. Zoologist Joah Madden has been studying the brains of bower birds, and believes he has found evidence to support Dr Miller's theories.
Producer Ros Smith. E-mail: [removed]