Each person is an idiom unto himself, an apparent violation of the syntax of the species.
Gordon AllportThe dog [in Pavlov's experiments] does not continue to salivate whenever it hears a bell unless sometimes at least an edible offering accompanies the bell. But there are innumerable instances in human life where a single association, never reinforced, results in the establishment of a life-long dynamic system. An experience associated only once with a bereavement, an accident, or a battle, may become the center of a permanent phobia or complex, not in the least dependent on a recurrence of the original shock.
Gordon AllportIf a person is capable of rectifying his erroneous judgments in the light of new evidence he is not prejudiced. Prejudgments become prejudices only if they are reversible when exposed to new knowledge. A prejudice, unlike a simple misconception, is actively resistant to all evidence that would unseat it. We tend to grow emotional when a prejudice is threatened with contradiction. Thus the difference between ordinary prejudgments and prejudice is that one can discuss and rectify a prejudgment without emotional resistance.
Gordon AllportOpen-mindedness is considered to be a virtue. But, strictly speaking, it cannot occur. A new experience must be redacted into old categories. We cannot handle each event freshly in its own right. If we did so, of what use would past experience be?
Gordon Allport