Involved in research on the effects of traditional medical education, Naranjo traveled briefly to the United States during a mission assigned by the University of Chile to explore the field of perceptual learning.

In 1962, Naranjo was at Harvard as a visiting Fulbright scholar at the Center for Studies of Personality and Emerson Hall, where he was a participant in Gordon Allport's Social Psychology Seminar and a student of Paul Tillich.

After a brief return to his native country, he was invited to Berkeley, California, for a year and a half to participate in the activities of the Institute of Personality Assessment and Research (IPAR).

It was during this period of time that he became an apprentice of Fritz Perls and part of the early Gestalt Therapy community, where he began conducting workshops at the Esalen Institute as a visiting associate.

[citation needed] In the years that led up to his becoming a key figure at Esalen, Naranjo received additional training and supervision from Jim Simkin in Los Angeles and attended sensory awareness workshops with Charlotte Selver.

"[4] Richard Evans Schultes allowed for Naranjo to make a special journey by canoe up the Amazon River to study yage with the South American Indians.

Also, an invitation from Ravenna Helson to examine the qualitative differences between books representative of the "Matriarchal" and "Patriarchal" factors lead to his writing The Divine Child and the Hero, which would be published much later.

He published three books on the Enneagram of Personality, as well as The End of Patriarchy, which is his interpretation of social problems as the expression of a devaluation of the nurturance and human instinct and their solution in the harmonious development of our "three brained" potential.

[11] While these legal actions were mostly unsuccessful, the United States Court of Appeals ruled that Ichazo was the original author of the application of the enneagram figure to a theory of ego fixations.

His 2010 book, Healing Civilization: Bringing Personal Transformation into the Societal Realm through Education and the Integration of the Intra-Psychic Family, is both a continuation of and a turning point in Naranjo's lifelong work.

In this book, with a foreword by Jean Houston, Naranjo explored what he saw as the root cause of the destruction of human civilization (as evidenced in the 2000s (decade) as war, violence, oppression of women, child abuse, environmental endangerment, etc.