An Integrative Theory of Psychotherapy: Research and Practice.

A dual-process personality theory and supporting research are presented. The dual processes comprise an experiential system and a rational system. The experiential system is an adaptive, associative learning system that humans share with other higher-order animals. The rational system is a uniquely human, primarily verbal, reasoning system. It is assumed that when humans developed language they did not abandon their previous ways of adapting, they simply added language to their experiential system. The two systems are assumed to operate in parallel and are bi-directionally interactive. The validity of these assumptions is supported by extensive research. Of particular relevance for psychotherapy, the experiential system, which is compatible with evolutionary theory, replaces the Freudian maladaptive unconscious system that is indefensible from an evolutionary perspective, as sub-human animals would then have only a single system that is maladaptive. The aim of psychotherapy is to produce constructive changes in the experiential system. Changes in the rational system are useful only to the extent that they contribute to constructive changes in the experiential system.