What if you were asked to describe images you saw in an inkblot or to invent a story for an ambiguous illustration--say, of a middle-aged man looking away from a woman who was grabbing his arm? To comply, you would draw on your own emotions, experiences, memories and imagination. You would, in short, project yourself into the images. Once you did that, many practicing psychologists would assert, trained evaluators could mine your musings to reach conclusions about your personality traits, unconscious needs and overall mental health.
But how correct would they be? The answer is important because psychologists frequently apply such "projective" instruments (which present people with ambiguous images, words or objects) as components of mental assessments, and the outcomes can profoundly affect the lives of the respondents. The tools often serve, for instance, as aids in diagnosing mental illness, in predicting whether convicts are likely to become violent after being paroled, in evaluating the mental stability of parents engaged in custody battles, and in discerning whether children have been sexually molested.