Gordon Emmerson had originally learned about the concepts of Ego State Therapy from the teachings of John and Helen Watkins. He practiced and taught Ego State Therapy for a number of years and wrote two books on Ego State Therapy, Ego State Therapy (2003), and Advances Skills and Interventions in Therapeutic Counselling (2007).
Even while he was teaching and writing about Ego States his conceptual understanding of states differed from those of the Watkins and from other Ego State Trainers. While Watkins saw Ego States originating during trauma, as split-offs from a core personality, Emmerson saw parts being formed in childhood through the repetition of coping skills.
The table below details some of the divergencies from Ego State Theory that were added by Emmerson.
See the section on differences between RT and EST to gain a better understanding of how different the two therapies have become.
In 2014 Emmerson concluded that the differences were too great in the concepts of the two therapies and in the treatments of the two therapies to keep them together. RT offers a nuanced understanding of pathology, a diagnostic framework, and specific treatment regimens for each diagnosis. It offers a complete theory of personality and interventions for the range of DSM-5 diagnoses.
Resource Therapy, The Complete Guide with Case Examples and Transcripts was published in 2014. The Resource Therapy Primer was also published that year.