The Rational Animal: How Evolution Made Us Smarter Than We Think

The Rational Animal

ALSO BY DOUGLAS T. KENRICK

Sex, Murder, and the Meaning of Life:

A Psychologist Investigates How Evolution, Cognition, and Complexity

Are Revolutionizing Our View of Human Nature
(2011)

Copyright © 2013 by Douglas T.
Kenrick and Vladas Griskevicius

Published by Basic Books,

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Designed by Jeff Williams

Library of Congress Cataloging-in-Publication Data

Kenrick, Douglas T.

The rational animal : how evolution made us smarter than we think / Douglas T.
Kenrick and Vladas Griskevicius.

pages cm

Includes bibliographical references and index.

ISBN 978-0-465-04097-1 (e-book) 1.
Reasoning (Psychology) 2.
Decision making.
3.
Evolutionary psychology.
I.
Griskevicius, Vladas.
II.
Title.

BF442.K46 2013

153—dc23

2013008954

DOUG:

For my sons, Dave and Liam,
who taught me a deeper lesson about rationality.

For my wife, Carol, who puts up with my irrationality.

For my mother-in-law, Jean Luce, who contributed the most
rational portion of Liam’s nature and who nurtures us all.

VLAD:

For my strong-willed father, who always finishes what he starts.

For my self-sacrificing mother, who prefers that
I not refer to people as animals.

For my nurturing wife, who liked the bit about
diamond-encrusted grillz.

For my curious children, who are confused about why
daddy’s name is next to a picture of an ape.

BUT WAIT, THAT’S NOT ALL!

DOUG AND VLAD:

For Bob Cialdini, our mentor and guru.

Contents

Introduction:Cadillacs, Communists, and Pink Bubble Gum

Why did Elvis gold-plate the hubcaps on his Cadillac?

1:Rationality, Irrationality, and the Dead Kennedys

What do testosterone-crazed skateboarders have in common with Wall Street bankers?

2:The Seven Subselves

Did Martin Luther King Jr. have a multiple personality disorder? Do you?

3:Home Economics Versus Wall Street Economics

Why did Walt Disney play by different rules than his successors?

4:Smoke Detectors in the Mind

Why is it dangerous to seek the truth?

5:Modern Cavemen

How can illiterate jungle dwellers pass a test that tricks Harvard philosophers?

6:Living Fast and Dying Young

Why do people who go from rags to riches often end up in bankruptcy court?

7:Gold Porsches and Green Peacocks

Do people buy a gold Porsche and a green Toyota Prius for the same reason?

8:Sexual Economics: His and Hers

When is a gain for the goose a loss for the gander?

9:Deep Rationality Parasites

How do snake oil salesmen exploit deep rationality?

Conclusion:Mementos from Our Tour

What’s in it for
moi?

Acknowledgments

Notes

References

Index

Introduction

Cadillacs, Communists, and Pink Bubble Gum

It has been said that man is a rational animal. All my life

I have been searching for evidence which could support this
.

—BERTRAND RUSSELL

A
RE YOUR DECISIONS
rational or irrational?

Let’s begin with a few quick questions.
Would you do any of the following:

•
You’re a young fellow with some rhythm who grew up poor in Mississippi.
Would you spend $785,400 on a Cadillac with gold-plated hubcaps and forty coats of paint custom-made from pearls, oriental fish scales, and diamond dust?

•
You’re a British woman living as an unemployed single mother.
You’ve been writing in your spare time, though, and your books have begun to sell like wildfire.
Would you give away your hard-earned money?

•
You’re an immigrant from a poor Communist country, where you once stood in line for four hours to buy your first banana.
Just after you first land in America on a Pan Am jumbo jet, you are taken to a giant supermarket full of unimaginably delicious and nutritious goods.
If your rich American relative offered you the opportunity to choose any one item to buy, would you purchase a pack of bubble gum?

•
You’re a college professor who has carefully protected his paltry retirement savings by putting them into safe bond accounts.
You have watched the stock market running up wildly for several years, and there are rumors among financial experts that the bubble is about to burst.
Would you choose that exact moment to take half of your already scarce retirement nest egg and put it into risky stocks?

•
You’re a wealthy Indian man in the state of Patiala with the legal right to marry as many women as you like.
You have ninety wives already.
Would you say enough is enough, or would you instead start looking for bride number ninety-one?

•
You’re a New Yorker working long hours as superintendent of an apartment building on East Eighty-sixth Street in Manhattan.
Would you spend all of your savings on lottery tickets?

If you didn’t answer yes to these questions, meet the folks who did:

•
Elvis Presley, the King of Rock ‘n’ Roll, who didn’t just buy the gaudiest Cadillac of all time but purchased over one hundred of them.

•
J.
K.
Rowling, author of the Harry Potter books, who gave away much of her hard-earned money, including writing one check for $15 million.

•
Vlad Griskevicius (one author of the book you now hold in your hands), whose first decision as a newly minted capitalist was to buy a pack of Bubblicious pink watermelon bubble gum.
And as for
that banana he stood in line for four hours to buy back in the old country, he ate it with the peel still on, thinking it would be downright stupid to throw away any part of so desirable a delicacy.

•
Doug Kenrick (the other author of the book in your hands), who, after watching his own retirement account grow sluggishly while the stock market shot up, transferred a large portion of those funds into the stock market in 2001, just in time to participate in a couple of historically unprecedented crashes in stock values.
Unless this book makes the
New York Times
best seller’s list, he’s now planning to retire some time after his seventy-ninth birthday, probably to a small hut in rural Ecuador.

•
Rajinder Singh, Sixth Maharajah of the Indian state of Patiala, who not only married a ninety-first wife, but didn’t stop saying “I do” until he hit bride number 365.

•
New York building superintendent Ray Otero, who not only squandered his savings, but continues to spend $30,000 a year on lottery tickets—without hitting a big win yet.

Some of these decisions, involving gold-plated hubcaps, $15 million donations, ninety-first wives, and $30,000 lottery budgets, might seem disconnected from normal people’s everyday decisions, which are more likely to involve whether to dine at Taco Bell or Pizza Hut.
Yet the decisions made by the King of Rock ’n’ Roll and the Maharajah of Patiala actually have a lot in common with those we all make every day.
Even seemingly absurd choices often mask deeper questions of profound significance about how people make decisions.

THE RATIONAL ANIMAL

Lurking behind those seemingly silly decisions about Bubblicious bubble gum, bags of lottery tickets, and diamond-dusted Cadillacs is a profoundly important question.
It is a question philosophers have pondered
for centuries, and one that is central to economics, psychology, and our daily lives: What are the underlying reasons for people’s choices?

Great thinkers from Aristotle and Descartes to Bertrand Russell and Oscar Wilde have all debated whether people are “rational animals.”
Philosophers, scientists, and pundits alike have focused on one side of the coin, vigorously arguing whether humans are or are not “rational.”
But the controversy has mostly overlooked the other side of the coin—the “animal” within the so-called rational animal.
This book is about that creature.

In the great debate about whether human decisions are rational or irrational, economists and psychologists have been obsessed over the surface features of our decisions—whether a person’s particular choice in a particular situation achieves that person’s goal.
For example, does the decision to buy a $2 lottery ticket or a shiny new car make a person richer or happier?
But to fully understand our decisions, we must dig below the surface and connect our present choices to the evolutionary past.
To understand how people make decisions, we ask a fundamental question neglected by traditional views: Why did the brain evolve to make the choices that it does?

Asking this question transforms the way we think about human decisions.
New scientific findings are revealing that our decision making, rather than being either rational or irrational, is characterized by
deep rationality
.
Our choices today reflect a deep-seated evolutionary wisdom, honed by our ancestors’ past successes and failures.
This book explores how the choices made in the modern world—by you, me, and Elvis Presley—are rooted in a finely orchestrated set of ancestral mechanisms that often operate outside our conscious awareness.

T
HIS NEW
way of thinking is based on two insights at the center of this book:

Insight 1: Human decision making serves evolutionary goals
.

The traditional way of thinking about human behavior is based almost completely on a consideration of people’s surface goals—getting a decent bargain on a pair of dress shoes, for example, or picking a fine restaurant for a date next Saturday. But humans, like all animals, evolved to make choices in ways that promote deeper evolutionary purposes. Once we start looking at modern choices through this ancestral lens, many decisions that appear foolish and irrational at the surface level turn out to be smart and adaptive at a deeper evolutionary level.

Insight 2: Human decision making is designed to achieve several very different evolutionary goals
.

Economists and psychologists have often assumed that humans seek a single broad goal: to feel good or to maximize benefits. In actuality, all humans pursue several very different evolutionary goals, such as acquiring a mate, protecting themselves from danger, and attaining status. This is an important distinction. Depending on which evolutionary goal they currently have in mind, consciously or subconsciously, people will have very different biases and make very different choices.

These deceptively simple insights represent a profound departure from earlier views of decision making.
They imply that our choices, like those made by Elvis Presley and Maharajah Rajinder Singh, are often subconsciously guided by deeper evolutionary goals.
And they suggest something even more radical: that there’s more than one you making decisions.
Although it feels as if there is just one single self inside your head, your mind actually contains several different
subselves
, each with a specific evolutionary goal and a completely different set of priorities.
You make decisions differently when your goal is wooing an attractive mate versus fending off the bad guys or climbing upward in the local status hierarchy.
Although the divided nature of your mind often leads you to appear inconsistent and irrational, many of your choices are, at a deeper evolutionary level, even more rational than the great philosophers ever imagined.