Human Paleopsychology

Kent G. Bailey             



...Can you imagine, language, once clear-cut and exact, softening and guttering, losing shape and import, becoming mere lumps of sound again?  And they walked erect with increasing difficulty.  Though they evidently felt ashamed of themselves, every now and then I would come upon one or other running on toes or fingertips, and quite unable to recover the vertical attitude.  They held things more clumsily; drinking by suction, feeding by gnawing,  drew commoner every day.  I realized more keenly than ever what Moreau had tld me about the "stubborn beast flesh."  They were reverting and reverting very rapidly.
H. G. Wells, The Island of Dr. Moreau.

Press for

Press for

     I wrote the first major book on Human Paleopsychology (1987). This approach is premised on two basic assumptions: first, human beings have an ancient and rich evolutionary history, and, second, that ancient history is thoroughly involved in everything we feel, think, and do…personally, politically, and morally. According to neuroscientist Paul MacLean’s venerable Triune Brain Theory, the human brain is composed of a primeval reptilian or lowest segment, a mammalian or mid-segment, and a human or neocortical segment. These three levels correspond roughly to instincts (reptilian), feelings (mammalian), and thoughts (neocortex). In 1983, I asked professor MacLean if it made sense to speak of “regressing down the triune brain” or “progressing up the triune brain”? He averred that it made perfect sense.
     My 1987 book, Human Paleopsychology: Applications to Aggression and Pathological Processes (Erlbaum) was dedicated to Paul MacLean and it outlined regression-progression theory in detail. The 542 pages of the 1987 book encompasses many fields, but the focus is on individual and social breakdowns of cultural, moral, religious, and economic systems that have taken thousands of years to reach their present form. Yet, with the slightest provocation in the form of social malaise, insult, drug or alcohol intake, exposure to pornography, or even sudden changes in the stock market, we see that good will, manners and civility, social order, and concern with “higher things” can disappear in an instant. The process whereby this occurs is termed phylogenetic regression and it refers to the sudden stripping away of the thin veneer of culture and the complementary re-activation of ancient evolved programs of selfishness, tribality and xenophobia, aggression, sexuality, and the like.

     In other words, when highly stressed and/or provoked, a person easily slips back into earlier evolutionarily adaptive programs that may have served our ancestors well in precultural times but are amoral/immoral, socially chaotic, and even pathological today. For example, sexual promiscuity and male gang behavior in hunting contexts may have served young men well 30,000 years ago, but activation of these tendencies today in the absence of moral, religious, legal, or other constraints can easily lead to rape, gang warfare, or even worst case scenarios like the “inexplicable” murderous actions of the two young men in Littleton, Colorado on April 20, 1999. The regression-progression model tries to make sense of these “inexplicable” events.
     Whereas regression is easily effected and merely needs a releasing stimulus, the development and maintenance of modern technological culture (phylogenetic progression) requires thousands of years to develop in the first place (e. g., the development of mathematics and its derivatives). Moreover, once developed such cultural material must be stored and then somehow transmitted to each new cultural generation. In our technological culture, twelve to 20+ years of painful, obsessive, self-deflating and instinct-discouraging formal schooling is required to even think about competing with other equally obsessed competitors for the economic goods of our capitalistic system.

     Moreover, below a certain SAT level, all of the enculturalization in the world may not yield a Harvard graduate. But even those with high SATs and privileged backgrounds are not immune to sudden and even murderous regressions such as those of the bright but alienated young men who perpetuated the Littleton tragedy. The thousands of dollars spent on their moral and intellectual education literally went up in the smoke of bullets flying and bombs going off. Their regressive ideology of nazism, tribality and xenophobia, alienation, and hatred nullified all of culture’s attempts to subdue their ancient demons. As they killed their classmates, nature had won over culture as easily as a Serengeti lion prevails over its next dinner. That is, easily.
     I feel that the social and political sciences must at some point come to grips with the issues raised by phylogenetic regression-progression theory.
                                                                               Selected References
Bailey KG: The concept of phylogenetic regression. Journal of the American Academy of Psychoanalysis 1978;6;5-35.
Bailey, KG: Psychobiological regression and aggression. Invited address at symposium in tribute of Paul D. MacLean held at the Chicago Academy of Sciences, May 1983.
Bailey KG: Human Paleopsychology: Applications to Aggression and Pathological Processes. Hillsdale, NJ: Erlbaum, 1987 (check this out on
Bailey, KG: Upshifting and downshifting the triune brain: Roles in individual and social pathology. In GA Cory and R Gardner, Jr., The Evolutionary neuroethology of Paul MacLean: Convergences and Frontiers (pp. 317-345), 2002.
Gilbert, P. & Bailey, KG.   Genes on the Couch: Explorations in Evolutionary Psychology,  Taylor and Francis, Philadephis, PA.  2000.


Comments on Kent G. Bailey's book
Human Paleopsychology

  "The next step in our understanding of human nature and psychology...a wonderful book indeed."  William Tillier, Canadian psychologist- 5 star review on
"The best on this subject I ever read in English.  It's a very rich and erudite book.  One can learn a lot about human evolution and its probable interplay with the human psyche..."  Paul V.  Katchalov, Russian psychiatrist- 5 star review on
"This book stimulates the imagination and provideds many bridges between disparate literatures. One of its greatest to make those of us applying evolutionary principles to complex human behavior think more about the conceptual nervous system."  From book review by famed and controversial Canadian IQ researcher, J. Philippe Ruston.
"I would like to express my sincere admiration and respect for your significant intellectual achievement by publishing your impressive book, Human Paleopsychology.  I congratulate you for this achievement."  Personal  communication from international author Michio Kitahara.  He also drew heavily from my theory in his controversial work, African Revenge: The Age of Regression and the Decline of the West.
My book's editor and chair of the psychology department at Harvard at the time,  Professor Brendan Maher,  wrote in the Forward that "This is likely to an important book; it is certain to be a controversial one."  He concluded that, "If, indeed, there are primitive biological propensities in man that are destructive of human life and happiness, then our task is to channel, control, and counter them as effectively as possible.  We cannot do this by refusing to recognize ther existence.  There is no doubt in my mind that the major and lasting contribution of Professor Bailey's book will be in his insistence that we look the data in the eye."
One of my stongest supporters in writing the book was Luigi Valzelli, distinguished Professor of Neuropharmacology at the Mario Negri Institute in Milan, Italy.  Not only did he offer great personal support, but he reviewed Human Paleopsychology  very positively in both Italian and English and made compelling comparisons between my work and his earlier book, Psychobiology of Aggression and Violence (1981).  His reviews found my book "fascinating,"  "controversial," and "very relevant" to the issue of the archaic bases of human aggression.
Dutch author and international expert on human aggression, Johan M. G. van der Dennen, refers frequently to my theory of phylogenetic regression in his work.  In his review of The Murderer Next Door: Why the Mind is Designed to Kill  by David Buss (2005), he lists regression theory among the five major theories of aggression discussed and sees it as especially relevant to "senseless," "predatory," and "enjoyable" forms of murder.  
British theologian and author J. Brian Tucker drew heavily from the "kinship" aspects of human paleopsychology in his recent book, "Remain in Your Calling": Paul and the continuation of social identities in I Corinthians"  (2011).  On page 58, he says, "Kent G. Bailey's concept of kinship formation, from the field of human paleopsychology, provides a unique framework from which to uncover Paul's approach to group formation."`
Controversial author and intellectual gadfly Camille Paglia read pre-publication materials for Human Paleopsychology and commented
"I was so amazed to see in what detail you had worked out my own similar intuitions about the dominance of the reptilian brain in criminal behavior.  The description of Ted Bundy seems to me totally persuasive."  She ended her personal letter with, "Our work is wonderfully complementary."  She also noted some parallels between my ideas and her best-selling book, Sexual Personae: Art and decadence from Neferti to Emily Dickinson.
Study these pages and become a paleopsychologist!
Kent G. Bailey [email protected]