The Elephant in the Brain - Book Summary and Highlights

The Elephant in the Brain

By Kevin Simler and Robin Hanson

Rating: 7/10

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Many of us have heard the expression, "the elephant in the room."  It refers to an important issue that everyone is aware of, but no one wants to acknowledge or address (a social taboo).  In this book, Kevin and Robin coin "the elephant in the brain" as, "an important but unacknowledged feature of how our minds work" (an introspective taboo).

Medicine in Developed Countries

The first example of this phenomenon has to do with the medical environment in developed countries.  They pose a question, "Why do patients spend so much on medical care?"  The obvious answer would be to get healthier.

However, as they dig into the research, they show that people in developed countries consume more medicine than required to stay healthy (doctor visits, drugs, test, etc.).  Studies have shown that people with free healthcare consume a lot more "medicine" and don't see correlated results to their overall health.

Studies have also proven the non-medical changes in lifestyle (diet, sleep, exercise, etc.), have a larger effect on your overall health.  People seem to be more interested in the appearance of good medical care rather than their overall health.

But why is this?  As they dig deeper, they conclude that medicine isn't just about health; it is also about conspicuous caring.  About showing how much you care by going well above and beyond what we require, even at a direct expense or little to no reward.

"The provocative conclusion is that healthcare isn't just about health; it's also a grand signaling exercise called conspicuous caring. If healthcare was only a transaction about getting well, you would expect patients to pay for (and doctors to prescribe) only treatments in which benefits exceed costs. Conspicuous caring provides an alternative explanation for demand that leads to consumption that exceeds the point of value. And in modern medicine, demand resulting from conspicuous caring can be masked by the real healing that often occurs." -John Mandrola M.D.

Social Animals

“Every man alone is sincere. At the entrance of a second person, hypocrisy begins.”—Ralph Waldo Emerson

This is not something we consciously observe.  Throughout the book, the authors cite examples where we subconsciously seek to maximize our social status (conspicuous caring is really showing others how healthy you are and how you take your health seriously, as this is a norm in our society).

Their thesis is that we are not only capable of acting on hidden motives; but that we are designed to act on them.  "Our brains are built to act in our self-interest while at the same time trying hard not to appear selfish in from of other people."  In order to hide the true selfish motivations, our brains keep us, our conscious minds in the dark.  "The less we know of our own ugly motives, the easier it is to hide them from others."

As social animals, we know that we are always being judged.  Others look at us and wonder if we would make good friends, allies, lovers, or leaders.  And they are looking to see why we behave the way we do and if we are selfish or look out of others.

Since we know we are being judged, we are eager to look good.  We highlight our "pretty" motives and downplay our "ugly" ones.  And not just in our actions, but in our thoughts.  "We deceive ourselves the better to deceive others."

They break the book into two parts.  In Part 1, the authors address why we hide our motives.  In Part 2, they explore examples of these hidden motives in everyday life.

Why We Hide Our Motives

“A man always has two reasons for doing anything: a good reason and the real reason.”—J. P. Morgan

Animal Behavior

To help understand why we hide our motives, the authors look to the animal kingdom.  They go into detail on the chimpanzee social grooming experience.  This is where the primates groom each other to keep areas they can't reach themselves clean.

However, studies have found the time spent grooming each other is more than is necessary to keep their fur clean.  In addition, they spend more time grooming each other than grooming themselves.

The accepted reasoning among experts is that social grooming isn't just about hygiene, but also about forming alliances.  This reasoning would also explain why social grooming lasts longer in larger groups.

Like humans, chimpanzees may not be aware that there is this underlying reasoning that goes hand in hand with the hygienic benefits.


Why do redwood trees grow so tall?  Many tree species grow tall to disperse their seeds more effectively or protect their leaves from animals looking for a snack, such as a giraffe.  They also grow looking for additional sunlight.

With the redwoods, this competition for sunlight creates some of the tallest trees in the world.  A single redwood, by itself in the forest, would quickly outgrow the surrounding trees and would not need to spend additional energy growing even taller.  However, when you have a forest of redwoods, each tree is competing for sunlight and therefore continues growing taller and taller, trying to get the fuel it requires to stay alive.

The human brain is the largest amongst our animal companions.  Our intelligence is exponentially higher.  If this evolution resulted from competition with these animals, we would look like a lone redwood in a forest of smaller trees.

Instead, the social brain hypothesis states human intelligence developed so quickly because of competition among each other in a variety of social and political scenarios.  We were competing for sunlight.  There are instinctual motivating factors in our decision making we are not always aware of.


Today's society has many norms.  There are no laws against cutting in line, but we frown upon it and judge those that caught in the act.  You will not be thrown in jail for being loud in a library, but you may be asked to keep your voice down.

But why do we follow these norms?  It goes back, like many things, to our ancient ancestors.  Hunter gatherers had to rely on each other for food, shelter, and protection.  While one person was out hunting, another was cooking or building shelter.  If problems arose, the group would defend each other (there is power in numbers).

Everyone was an equal and contributed to the good of the whole.  If someone decided that they no longer wanted to contribute, but still took advantage of eating the food others caught and sleeping in shelters others built and maintained, they would throw them out of the group and left to fend for themselves.  Breaking the norms of that period would be a death sentence.

Today's norms do not have such dire consequences.  But they do limit competition amongst ourselves.  Bragging, currying favor, workplace politics, selfish motives; these are norms in our society that we frown upon.  However, we still look for ways to subvert them.


While most people do not break or circumvent larger rules (robbery, arson, murder), we often violate smaller norms (jaywalking, taking supplies from work, using recreational drugs).  Why do we cheat?  Because it allows us to get all the benefits with none of the typical costs.

Carly Geehr, a member of the US National Swim team, said, "Nearly 100% of elite competitive swimmers pee in the pool.  Some deny it, some proudly embrace it, but everyone does."  Why would they break this norm?  It is too troublesome to take bathroom breaks in the middle of practice.

The human brain has continued to evolve due to this cat-and-mouse game of cheating and looking for the cheaters.  Our ancient ancestors are sure to have put a little more food aside for themselves, even though the risk was getting thrown out of the group.  They found ways to cheat and not get caught.  Others in the group were more skeptical and found ways to detect these cheaters.

So while we know intra-species competition is why our brains and our intelligence grew and we know norms developed to limit that competition, this constant cheating and detection competition furthered our development.

Hidden Motives in Everyday Life

The second part of this book dives into examples of these hidden motives in:

  • Body Language (non-verbal communication)
  • Laughter
  • Conversation
  • Consumption
  • Art
  • Charity
  • Education
  • Medicine
  • Religion
  • Politics

I will not write about each of these topics in this review as the authors even state that you can read Part 2 of the book can in any order or just those topics that interest you.  They provide a thorough analysis into each topic, showing examples of how we use each one, usually subconsciously, and what it subconsciously says to others.


The Elephant in the Brain provides a unique way of looking at mundane things we do every day and what we are "saying" to others by those actions.  It is not a life-changing study, nor does it provide any set of instruction on how to change our actions.  Instead, it provides a unique insight into why and how we do them.

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