A human laboratory test of eysenck's theory of incubation: A search for the resolution of the neurotic paradox

A number of recent attempts have been made by neobehaviorists to resolve the neurotic paradox by incorporating a nontraditional learning principle. Eysenck's concept of incubation represents one of these attempts and is the subject matter of this paper. Incubation theory states that under certain conditions exposure to a fear-provoking conditioned stimulus (CS) can result in a substained growth of fear. This concept is used to explain extreme avoidance (symptom) maintenance in extinction. To test this theory, three conditions identified by Eysenck and considered critical to the development of incubation were manipulated in a classical conditioning paradigm: unconditioned stimulus (UCS) intensity, duration of CS exposure, and individual differences in neuroticism/introversion. Both physiological and self-report fear measures were taken. Results indicated that, contrary to incubation theory, fear extinguished in all groups. Long durations of CS exposure were found to be more effective than brief exposure in reducing fear of highly fearful subjects. Clinical implications for therapies using fear exposure such as flooding and implosion were discussed, as well as the resolution of the neurotic paradox via established learning principles.