The association of white with virtue and black with sinfulness is deep

THE virtuous are often said to be as “pure as the driven snow” while villains are frequently described as having hearts of coal or blackened souls. And the metaphor is made flesh (or, at least cloth) in many plays and films where the baddy wears black and the goody white. But how deep does the metaphor actually run, psychologically speaking?

That is the question which was asked by Gary Sherman and Gerald Clore of the University of Virginia. They were pondering a well-known tendency, called the “Macbeth effect”, for people to want to clean themselves physically if they have acted unethically or even had thoughts of corrupt behaviour. (The name comes from the scene in Shakespeare’s play in which Lady Macbeth desperately tries to wash phantom bloodstains from her hands after encouraging her husband to murder the king.) This association of cleanliness with moral probity is further bound up with the now well-established link between moral disgust (eg, at unusual sexual practices) and physical disgust (eg, at handling dirty objects or eating polluted food). The researchers’ ponderings led them to wonder if the moral roles of black, which is roughly the colour of dirt, and white, which shows up the dirt so well, were connected with the Macbeth effect. …