ABSTRACT
The possibility that some passing mood of elation or depression, of anxiety or fatigue, has confounded a test result is even greater in the personality and motivation realm than in the scholastic achievement field. Indeed, we must recognize that every personality measurement is taken at a time when the individual is deviant, by some small mood state, from his true average position. Classical 'brass instrument' experimenters have similarly observed, as by-products of their work on, for example, perception, or learning, that certain behaviours tie up with apparent individual differences of personality. Many psychologists have had an almost mystical belief that a person's choices in art, in particular, constitute a sensitive personality indicator, especially of his temperament. 'Life style' and the belief that the whole personality can be inferred from a scrap of handwriting or the lilt of a voice continues to fascinate many, just as does extra-sensory perception or hypnotism.
