Stress-induced recovery of fears and phobias.

Accounts of human fears and phobias based on current conditioning models using data from adults are examined and found wanting. Instead, the characteristics of human phobias resemble the kind of learning found during the amnesic period of infancy. As certain neural systems mature, conditioning begins to exhibit adult characteristics: context dependency, sharp generalization, and rapid extinction. Al-though direct behavioral control by the early learning systems wanes, the adult learning system seems to be structured at least/partially through the lasting influence of infantile experience. Under (hormonal) stress, residues of early experience are reinstated and incorporated into adult memory where they directly control behavior. This control exhibits infantile characteristics. The evidence suggests that once ac-quired, such conditional fears might never be eliminated using traditional extinction or counterconditioning procedures. The view leads to a renewed emphasis upon the role of experience in human development, accepting the disproportionate im-portance of infant experience as the foundation upon which subsequent learning and cognitive function rest.