Personality and the Brain

This page offers writings on an hypthesis for connecting the Enneagram theory of personality with the brain. These writings are in the form of a paper, and a book. Essentially, the paper summarizes the book.

The paper: The Enneagram and Patterns of Asymmetric Dominance in Orbitofrontal Cortex and Amygdala, December 2007 (7 pages)

The book: Personality and the Brain: A hacker’s journey through the Enneagram and the emerging brain research, December 2005 (200+ pages)

Copyright © 2005, 2007, 2015 by Peter Savich

These works are licensed under a Creative Commons License.



12/15/07: The Wikipedia Police

After two years of a Wikipedia link to this page, a Wikipedia "policeman" has taken upon himself/herself to delete any mention of brain research on the Enneagram. For your entertainment, here is the discussion thread between this person and myself:

12/15/07: Eric Lombrozo's Paper

If you find my paper and/or book at all interesting, you'll definitely be interested in the paper Prefrontal Cortex Dissociation from Amygdala and Personality Types by Eric Lombrozo. Check it out.

12/13/07: Paper

After two years, I finally got around to writing up a short paper summarizing the main points of the book. Basically, I started with the abstract of the book, and fleshed that text out into a (hopefully) readable paper. Happy reading.

06/17/07: Oops

In my note of 01/29/07 below, I wrote: "Worse case scenario, krytyk and I keep up an endless 2-person discussion." Actually, that did happen. But it wasn't, by far the worse case scenario. Indeed, the tsunami of spam that the board received and which led to me lock the board in April wasn't even the worse case scenario. Nope. The worse case scenario happened this morning when I logged onto my phpbb discussion board to try to figure out how to delete only the bucket load of spam comments while keeping the great discussions that krptyk pretty much drove. Well I finally did figure out howto do that -- right after I accidenty deleted the whole thing. Well, anyway, no big loss. Seems krytyk and I are just about the only humans on the planet interested in digging this deeply on both the Enneagram and neuroscience. Lots of folks seem endlessly interested in either topic; but few in both.

01/29/07: Ask and ye shall receive

Well, as you can see, last September I begged for comments on the book. Today, commenter krytyk submitted no less than 17 (!) excellent comments on the book. Well, it soon became clear that this hokey little blog commenting stop-gap system needs to graduate into a formal discussion board. Worse case scenario, krytyk and I keep up an endless 2-person discussion. But here's hoping that more of you all will join in and give us your two cents. Thanks! Peter

09/30/06: Please Comment!

Looking at my site statistics for 2006, it seems that over 200 people have downloaded the PDF version of this book over the last nine months. Moreover, during September, there seemed to be a spike in this activity. I'm suspecting this spike might have something to do with the start of the school year this month. Whatever the case, I figure it's time for some robust discussion of the arguments presented in the book. Specifically, I'm particularly interested in reading:

I just noticed that the Comments link below for the entire book had been misplaced. Maybe that partly explains the dearth of comments thus far. Anyway, I've corrected it. Also, I've placed that link at the top of this page. Please use this link to enter your comments on anything to do with the book. Thanks! I look forward to hearing from you. Peter

Personality and the Brain is a book that I've been writing for the past few years. It's about the Enneagram and the brain. Specifically, the book presents a model for linking the Enneagram to current brain research on PFC and amygdala asymmetry.

I had originally planned to find a publisher for it. But my first child (a daughter) was born on November 30, 2005. Suddenly, the top spot on my priority list for the foreseeable future was occupied. That pushed everything else lower down the list, and some items just plain fell off. This book is one of those items ...

... that is, unless you show some interest that motivates me to finish it. Although unfinished, the meat of the book is done, and the model is reasonably clear. So if you're interested in this topic, there's enough here for you sink your teeth into.

Below is the book in both HTML and PDF format. You can either download the entire book (it's 1.2MB in size) in PDF form, download the book chapter by chapter in PDF form, or surf through the book chapter by chapter in HTML form. The HTML links are the titles of the chapters, while the PDF forms are accessed via the "pdf" links.

In addition, I've set up a link to my blog for the book, plus links for individual chapters, to enable you to comment on the book as whole, as well as chapter by chapter.

Donate? Huh?

Personality and the Brain: A hacker's journey ... [Download Entire Book (1.2MB) | Comment]

Introduction: History is Calling

Acknowledgements, Table of contents, Preface, and Introduction.


A 7-page summary of the book.

Part One: Promising Territory for Science

Chapter 1: Enneagram Basics

A quick introduction to the Enneagram theory of human personality.

Chapter 2: Basic Fears

Description of the core of the Enneagram: the different types of fears that define personality.

Chapter 3: Triads

An in-depth analysis of the aspect of the Enneagram that makes it amenable to neuroscience. My model for linking the Enneagram to the brain is introduced here.

Part Two: The Seat of Personality

Chapter 4: A Primer on the Brain

A survey of basic information on the brain relevant to this book.

Chapter 5: Mood

An in-depth analysis of current neuroscientific findings concerning the role of the prefrontal cortex (PFC) in manifesting optimism and pessimism.

Chapter 6: Fear

An in-depth analysis of current neuroscientific findings concerning the role of the amygdala in manifesting aware fear and unaware fear.

Part Three: Connecting the Dots

Unfinished Business

Chapters I haven't started yet. Should I do so? Let me know by leaving a comment.


A rough list of citations to the papers and books this book relies upon.