Intro & Table of Contents

It’s dessert time!

There is a juicy apple in front of you, and a slice of chocolate cake.

You are free to choose.

Or are you?

The choice was made for you – hundreds of millions of years ago!

This book is about the commonalities all 8,000,000,000 people on earth share.

Our ancestors were molded by ruthless survival pressures from the earliest days of life on the planet. Adaptations that worked long ago are still inside of us – also shared with insects and reptiles. Later additions are common to all mammals from the tiniest shrews to the most massive whales. Some capabilities were bolted on relatively recently, and are only shared with our primate cousins. And the runaway explosion of humans on the planet can only be explained by our bizarre species-level evolution.

The only way to understand how our brains work is to examine the complete evolutionary arc.

I don’t care if you are young or old, rich or poor, introverted or extroverted. It is not about our individual differences. This book describes the basic operating system of how we all deal with life.

Drop a rock. It falls and hits the ground.

Once you understand brain evolution, many of our behaviors will become more predictable. To a scary degree, we are reactive animals ruled by passions, and not the rational geniuses with free will that we like to imagine.

First the bad news: The notion that people make decisions and choices to maximize objective self-interest has been demolished. People are not rational – far from it.

Now the good news: We are finding out exactly how and why we act in these seemingly irrational ways. In other words, there is a method to our seeming madness.

My view of the brain is heavily influenced by evolutionary biology and psychology. I don’t believe we have arrived at a perfect brain design, or that humankind deserves an exalted and special place in the universe. Rather, we are a band of super-cooperative apes who have come to dominate the planet. In the process we have wiped out whole ecosystems in our voracious destructiveness. At this moment we are by far the most dominant force shaping the very destiny of life on earth.

We evolved for a particular environment, but our rapid social advances and mushrooming populations have created a bewildering new world. On the timescale of this dizzying change, evolution has effectively stopped, and we must rely on what has gotten us this far. By retracing the path that our distant ancestors took to get here, we can understand the stunning abilities and glaring weaknesses which we have inherited.

Sometimes our reactions and responses are appropriate and uncannily helpful. In the blink of an eye we can assess complex situations and reach critical life-or-death decisions. At other times, we are seemingly our own worst enemies – repeating the same mistakes, even when we know the results will be counterproductive, or even deadly.

Unlocking the true nature of the human brain is the last frontier. Recent work in fields such as biology, neuroscience, evolutionary psychology, medical imaging, social science, and behavioral economics is combining to show us the inner workings of this evolutionary marvel.

This book is designed for you – the curious and intelligent searcher for truth.

I want to give you the essentials, and draw you a map of the wondrous terrain inside of the human mind.

You will forever be altered by the journey we are about to undertake together. It may seem like an alien landscape at first. But you will gain valuable perspectives which will allow you to live your life with a new appreciation of what makes us tick.

Forget the advanced technology all around you – let’s explore inside of the bony skull which guards the treasures within…

Get ready, it’s going to be a wild ride!


Table of Contents

Why You Should Read This Book


Part I – Foundations

Chapter 1 – The Lie of Rationality

The big lie

Emotions and decisions

We are the products of evolution

Chance and circumstance

Chapter 2 – The Big Picture of Brain Evolution

Life without brains

Why do we need a brain?

Following the recipe

Key brain systems

Simplifying to make it useful

Chapter 3 – Brain Basics

Gross anatomy

Experience wires the brain

Use it or lose it

Chapter 4 – How We Learn and Remember

The purpose of memory

Stages of memory




Forgetting and distortion

There is no detailed life recording

Chapter 5 – This Is Your Brain on Drugs

Emotions are signposts for survival

Repetition and emotion – the two key ways to learn

The treadmill of unhappiness

Altered states

The arc of addiction

Feeding and energy balance

Food and emotions

Chapter 6 – The Chemistry of Happiness

Older and newer brain chemicals

Dopamine – motivation and energy control

Updating our mental model

The pleasure circuit in more detail

Endorphins – emergency pain suppression

Oxytocin – attachment and outgroups

Serotonin – social dominance and hierarchy

Happiness gone wrong

Part II – Reptiles and Shrews

Chapter 7 – The Autopilot and the Power of Pain

Lizards and shrews

The reptile brain – avoiding harm and ignoring most events

Fear and unhappiness

Sore losers

Chapter 8 – Demystifying Risk

Relativity and reference points

Loss aversion

Sure things and surprises

Chapter 9 – The Emotional Life

Embodied emotions

Personal life experiences

Cultural overlays and interpretation

Chapter 10 – Safer in the Herd

Pluses and minuses of herds

Isolation equals death

Attachment and affection

Avoidance and approach

Status and dominance

Chapter 11 – Good Night, Sweet Dreams

The universal need for sleep

Human sleep

The effects of not sleeping

REM sleep

Dreams as a rehearsal for dangerous events

Remembering, learning, and creativity

Chapter 12 – Monkey See, Monkey Do

Mirror neurons


Getting into other people’s heads

Empathy and sympathy

Part III – Clumsy Bigheads

Chapter 13 – Humble Beginnings

Aren’t we amazing?!

Other archaic humans

Brain drain

Chapter 14 – Big Babies

Death by cannonball

Neonatal freaks

Helpless learners

Chapter 15 – Sexy Apes

Are we sluts?

Hunting, gathering, and screwing

High-risk sex

Sexual asymmetry

Men’s signaling

Women’s signaling

The biology of love

Chapter 16 – Let Me Tell You a story

The functions of language

Storytelling and mindreading

Order out of chaos

Simulating social experiences

Gossip, tribes, and civilizations

Chapter 17 – The Dance Between Your Brains

Characteristics of the primal brain

Characteristics of the conscious brain

Part IV – Hypersocial

Chapter 18 – How We Evolved to Be Cultural Creatures

The common narrative of human dominance

The real story – cultural and genetic co-evolution

Big brains evolved for cooperative learning

How culture and genes caught fire

Chapter 19 – The Building Blocks of Culture

Whom to learn from


Blind faith

Social rule followers

Chapter 20 – The Social Network

Social thinking

No one is an island

The need for belonging and validation

Peer pressure and conforming

Ingroups and outgroups

Chapter 21 – Ownership, Fairness, and Favors

Ownership and possession

Fairness or revolt

Social and transactional spheres

Reciprocity and obligation

Chapter 22 – Conformity and Integrity

The inner lives of others

Group power

Integrity and consistency

The seeds of voluntary action

Making a public stand


Part V – What’s Next?

Chapter 23 – How to Be More Primal

Get proper sleep

Be in your body

Regularly access your intuition and emotions

Avoid artificial addictions

Don’t be a loner

Learn from others and teach something

Chapter 24 – A Personal Challenge

Appendix – Recommended Reading