Peggy Pace graduated from the University of Washington in 1969 with a Bachelor of Science degree in Chemistry. She eventually returned to school and in 1985 she received a Master of Art's degree in Counseling Psychology from Antioch University. Pace spent much of her career between 1985 and 2003 counseling adults who suffered from symptoms of childhood trauma. She developed the Lifespan integration technique after realizing that many of her patients' present-day problems were due to body memories of unintegrated and unresolved past traumas. Lifespan Integration (LI) is a therapeutic process which enables trauma survivors to integrate body memory of past experiences into their present-day selves, resulting in more coherence in their self-systems and more fluid life narratives.
Pace published the first edition of her book, Lifespan Integration: Connecting Ego States through Time, in 2003. After her book was published Pace received many requests from psychotherapists who wished to learn this revolutionary new method for healing psychological trauma. In response to these invitations, Pace traveled and taught her method to therapists in many parts of the US, Canada, France, Spain, Sweden, England, Ireland, and Russia. Today Lifespan Integration training courses are being offered in many countries.