Mastermind: How To Think Like Sherlock Holmes Book Summary



“Did you ever stop to think, and forget to start again?”  ~Winnie the Pooh

You can think like Sherlock Holmes.

If you know how.

In Mastermind: How To Think Like Sherlock Holmes, Maria Konnikova teaches you how to apply the thinking methods and techniques of Sherlock Holmes to your everyday life.

In a nutshell, Maria Konnikova puts twenty-first century neuroscience and psychology on your side.

With some self-awareness and a little practice, you can sharpen our perceptions, solve difficult problems, and enhance your creative powers.

By walking through the science of memory, creativity, and reasoning, and using Sherlock Holmes to bring the ideas to life, Maria Konnikova helps you master your own mind.

Konnikova helps us rise above and avoid the pitfalls of the Watson mind through proven practices so we can free ourselves from our unconscious biases and our habitual distractions.

Mastermind is an journey of epic proportion.  As such, this is an epic book review to help you see the breadth and depth that Konnikova covers, with enough detail so you can see why this is one of those books that you don’t want to miss, and will serve you for life.

It’s one of those books that can help you for the rest of your life, for the best of your life.

Let’s dive in …

What’s In It For You

  • How to pay attention with skill
  • How to optimize your thought process
  • How attention is a limited resource and how it fails us
  • How to avoid common pitfalls of cognitive biases, bleeps, and blunders
  • How to improve how you form, retain, and retrieve memories
    How to use meditation to increase creativity and imaginative capacity
  • How to use curiosity and play to create more creative insights
  • How to improve your self-awareness so you can understand your thought patterns, strengths, and weaknesses

Chapters at a Glance

  • Chapter 1 – The Scientific Method of the Mind
  • Chapter 2 – The Brain Attic: What Is It and What’s in There?
  • Chapter 3 – Stocking the Brain Attic: The Power of Observation
  • Chapter 4 – Exploring the Brain Attic: The Value of Creativity and Imagination
  • Chapter 5 — Navigating the Brain Attic: Deduction from the Facts
  • Chapter 6 – Maintaining the Brain Attic: Education Never Stops
  • Chapter 7 – The Dynamic Attic: Putting It All Together
  • Chapter 8 – We’re Only Human

Key Features

Here are some of the key features of Mastermind: How To Think Like Sherlock Holmes:

  • Actionable.   Konnikova turns theory into practice throughout the book.
  • Deep.  It’s super deep.  You’ll learn more about your mind and how it works, flaws and all, in a way that puts the story together with breadth and depth.
  • Focused.   The book is focused on mindful practices and thinking techniques.   It’s a system for elevating your thinking to the highest level.
  • Relevant.   If you want to use your brain or think better, this book is relevant in every way.
  • Research-based.  The book is based on research and science.  It’s not just a neat idea with opinions thrown in.  It’s a carefully crafted guide to making the most of the research on how we can think with skill.
  • Results-driven.  It’s all about getting results.  While Konnikova shares plenty of theories and examples of research, she always shows us how they are relevant and impact our thinking in practical ways, so we can produce better results.

Here is a sampling of some of my favorite nuggets from the book …

Start with the Basics

Always start with the basics.  They give you a firm foundation, and it’s actually slowing down to speed up.

Konnikova writes:

“Holmes recommends we start with the basics.  As he says in our first meeting with him, ‘Before turning to hose moral and mental aspects of the matter which present the greatest difficulties, let the enquirer begin by mastering more elementary problems.’ 

The scientific method begins with the most mundane seeming of things: observation. 

Before you even begin to ask the questions that will define the investigation of a crime, a scientific experiment, or a decision as apparently simple as whether or not to invite a certain friend to dinner, you must first explore the essential groundwork

It’s not for nothing that Holmes calls the foundations of his inquiry elementary.’  For, that is precisely what they are, the very basis of how something works and what makes it what it is.”

Hypothesis Generation

Hypothesis generation is a skill.  Don’t just make up random guesses.  Apply what you know and observe to come up with useful and testable hypotheses.

Konnikova writes:

“Whatever the specific issue, you must first define and formulate it in your mind as specifically as possible – and then you must fill it in with past experience and present observations…

Only then can you move to the hypothesis-generation point.  This is the moment where the detective engages his imagination, generating possible lines of inquiry into the course of events, and not just sticking to the most obvious possibility…

But you don’t just start hypothesizing at random: all the potential scenarios and explanations come from the initial base of knowledge and observation

Only then do you test.  What does your hypothesis imply? 

At this point, Holmes will investigate all lines of inquiry, eliminating them one by one until the one that remains, however improbable, must be the truth.”

The Scientific Method in a Nutshell

You can apply the scientific method to your thoughts.

Konnikova writes:

“That, in a nutshell, is the scientific method: understand and frame the problem; observe; hypothesize (or imagine); test and deduce; and repeat

To follow Sherlock Holmes is to learn to apply that same approach not just to external clues, but to your every thought – and then turn it around and apply it to the every thought of every other person who may be involved, step by painstaking step.”

The Two –System Basis of Our Mind

There’s the lazy and emotional thinking system, and the logical and deliberate thinking system.

Konnikova writes:

“Most psychologists now agree that our minds operate on a so-called two-system basis.  One system is fast, intuitive, reactionary – a kind of constant fight-or-flight vigilance of the mind. 

It doesn’t require much conscious thought or effort and functions as a sort of status quo autopilot.  The other is slower, more deliberate, more thorough, more logical – but also much more cognitively costly. 

It likes to sit things out as long as it can and doesn’t step in unless it thinks it absolutely necessary.”

The Watson System and the Holmes System

The Watson mind is easy, and it comes to us naturally.  It’s our default mode.  The key is to break from the Watson mode, and learn to think the Sherlock way.  It takes work, but it helps us to become better thinkers and to reach our aspirational selves.

Konnikova writes:

“I’m going to give the systems monikers of my own: the Watson system and the Holmes system

You can guess which is which. 

Think of the Watson system as our naïve selves, operating by the lazy thought habits – the ones that come most naturally, the so-called path of least resistance – that we’ve spent our whole lives acquiring. 

And think of the Holmes system as our aspirational selves, the selves that we’ll be once we’re done learning how to apply his method of thinking to our everyday lives – and in so doing break the habits of our Watson system once and for all.”

How We Disbelieve Something

To disbelieve something, we first have to believe it’s true.

Konnikova writes:

“When we think as a matter of course, our minds are preset to accept whatever comes to them.  First we believe, and only then do we question. 

Put differently, it’s like our brains initially see the world as a question

Put differently, it’s like our brains initially see the world as a true/false exam where the default answer is always true

And while it takes no effort whatsoever to remain in true mode, a switch of answer to false requires vigilance, time, and energy

Psychologist Daniel Gilbert describes it this way: our brains must believe something in order to process it, if only for a split second.  Imagine I tell you to think of pink elephants.  You obviously know that pink elephants don’t actually exist.  But when you read the phrase, you just for a moment had to picture a pink elephant in your head.  In order to realize that it couldn’t exist, you had to believe for a second that it did exist

We understand and believe in the same instant.”

Correspondence Bias: We Believe Things Way Too Easily

Don’t shoot the messenger.  Unfortunately, even when we know not to do that, we do it anyway.

Konnikova writes:

“In fact, not only do we believe everything we hear, at least initially, but even when we have been told explicitly that a statement is false before we hear it, we are likely to treat it as true. 

For instance, in something known as the correspondence bias (a concept we’ll revisit in greater detail), we assume that what a person says is what that person actually believes – and we hold on to that assumption even if we’ve been told explicitly that it isn’t so; we’re even likely to judge the speaker in its light

More disturbing still even if we hear something denied – for example, Joe has no links to the Mafia – we may end up misremembering the statement as lacking the negator and end up believing that Joe does have Mafia links – and even if we don’t, we are much more likely to form a negative opinion of Joe. 

We’re even apt to recommend a longer prison sentence for him if we play the role of jury.  Our tendency to confirm and to believe just a little too easily and often has very real consequences both for ourselves and for others.”

To Think Better, We Have to Want To

To think better, we have to want to think better.

Konnikova writes:

“But in order to break from that auto-piloted mode, we have to be motivated to think in a mindful, present fashion, to exert effort on what goes through our heads instead of going with the flow. 

To think like Sherlock Holmes, we must want, actively, to think like him.”

Motivated Minds Always Outperform

Nothing succeeds like motivation.  Do you have “the rage to master”?

Konnikova writes:

“Motivated subjects always outperform. Students who are motivated perform better on something as seemingly immutable as the IQ test – on average, as much as .064 standard deviation better, in fact.  Not only that, but motivation predicts, higher academic performance, fewer criminal convictions, and better employment outcomes. 

Children who have a so-called “rage to master” – a term coined by Ellen Winner to describe the intrinsic motivation to master a specific domain – are more likely to be successful in any number of endeavors, from art to science.

If we are motivated to learn a language, we are more likely to succeed in our quest. 

Indeed, when we learn anything new, we learn better if we are motivated learners.  Even our memory knows if we’re motivated or not; we remember better if we were motivated at the time the memory was formed.  It’s called motivated encoding.”

Experts Have Superior Memory in their Field of Choice

Experts have useful patterns at their mental fingertips, that reflect their expertise.

Konnikova writes:

“Think of the phenomenon of expert knowledge: experts in all fields, from master chess players to master detectives, have superior memory in the field of choice.  Holmes’s knowledge of crime is ever at his fingertips. 

A chess player often holds hundreds of games, with all of their moves, in his head, ready for swift access

Psychologist K. Anders Ericsson argues that experts even see the world differently within their area of expertise: they see things that are invisible to a novice; they are able to discern patterns at a glance that are anything but obvious to an untrained eye; they see details as part of a whole and know at once what is crucial and what is incidental.”

Our Brain Attic’s Structure

How we structure our brain’s attic can help us store, sort and retrieve information more effectively.  But to make it more effective, we have to make it a conscious effort and discipline.

Konnikova writes:

“The attic can be broken down , roughly speaking, into two components: structure and contents.  The attic’s structure is how our mind works: how it takes in information.  How it processes that information.  How it sorts and stores it for the future.  How it many choose to integrate it or not with content that are already in the attic space.

Unlike a physical attic, the structure of the brain attic isn’t altogether fixed.

It can expand, albeit not indefinitely, or it can contract, depending on how we use it (in other words, our memory and processing can become more or less effective).  It can change its mode of retrieval (How do I recover information I’ve stored?).  It can change its storage system (How do I deposit information I’ve stored?).  It can change its storage system (How do I deposit information I’ve taken in: where will it go? how till it be marked? how will it be integrated?).

At the end, it will have to remain within certain confines – each attic, once again, is different and subject to its unique constraints – but within those confines, it can take on any number of configurations, depending on how we learn to approach it.”

Our Brain Attic’s Contents

The contents of our mind are not static, and can change over time.

Konnikova writes:

“The attic’s contents, on the other hand, are those things that we’ve taken in from the world and that we’ve experienced in our lives.  Our memories.  Our past.

The base of our knowledge, the information we start with every time we face a challenge.

And just like a physical attic’s contents can change over time, so too does our mind attic continue to take in and discard items until the very end.

As our thought process beings, the furniture of memory combines with the structure of internal habits and external circumstances to determine which item will be retrieved from storage at any point.

Guessing at the contents of a person’s attic from his outward appearance becomes one of Sherlock’s surest ways of determining who that person is and what he is capable of.”

Memory:  The Broad Idea

What’s the big idea behind how memory works?

Konnikova writes:

“The specifics aren’t nearly as important as the broad idea.  Some things get stored; some are thrown out and never reach the main attic

What’s stored is organized according to some associative system – your brain decides where a given memory might fit – but if you think you’ll be retrieving an exact replica of what you’ve stored, you’re wrong. 

Contents shift, change, and re-form with every shake of the box where they are stored.”

Memory: The Specifics

What are the specific bits and pieces that help us store, organize, and recall information when we need it?

Konnikova writes:

“Today, it’s commonly accepted that memory is divided into two systems, one short- and one long-term, and while the precise mechanisms of the system remain theoretical, an attic-like view – albeit a very specific kind of attic – may not be far from the truth. 

When we see something it is first encoded by the brain and then stored in the hippocampus – think of it as the attic’s first entry point, where you place everything before you know whether or not you will need to retrieve it. 

From there, the stuff that you either actively consider important or that your mind somehow decides is worth storing, based on past experience and your past directives (i.e., what you actually consider important), will be moved to a specific box within the attic, into a specific folder, in a specific compartment in the cortex – the bulk of your attic’s storage space, your long-term memory. 

That is called consolidation. 

When you need to recall a specific memory that has been stored, your mind goes to the proper file and pulls it out.  Sometimes it pulls out the file next to it, too, activating the contents of the whole box or whatever happens to be nearby – associative activation.  Sometimes the file slips and by the time you get it out into the light, its contents have changed from when you first placed them inside – only you may not be aware of the change.  In any case, you take a look, and you add anything that may seem newly relevant.  Then you replace it in its spot in its changed form.  Those steps are called retrieval and reconsolidation, respectively.”

We Only Know What We Can Recall

What good is information is you can’t remember it?

Konnikova writes:

“It’s important to keep one thing in mind: we know only what we can remember at any given point.  In other words, no amount of knowledge will save us if we can’t recall it at the moment we need it.”

Motivation to Remember (MTR):  The Scooter Libby Effect

Motivation plays a key role in what we remember, and how we remember it.

Konnikova writes:

“Psychologist Karim Kassam calls it the Scooter Libby effect: during his 2007  trial, Lewis ‘Scooter’ Libby claimed no memory of having mentioned the identity of a certain CIA employee to any reporters of government officials. 

The jurors didn’t buy it. 

How could he not remember something so important? Simple.  It wasn’t nearly as important at the time as it was in retrospect – and where motivation matters most is at the moment we are storing memories in our attic to begin with, and not afterward. 

The so-called Motivation to Remember (MTR) is far more important at the point of encoding – and no amount of MTR at retrieval will be efficient if the information wasn’t properly stored to begin with.  As hard as it is to believe, Libby may well have been telling the truth.”

Attentional Blindness

Even the obvious can escape us.

Konnikova writes:

“The phenomenon is often termed attentional blindness, a process whereby a focus on one element in a scene causes other elements to disappear; I myself like to call it attentive inattention

The concept was pioneered by Ulric Neisser, the father of cognitive psychology.  Neisser noticed how he could look out a window at twilight and either see the external world or focus on the reflection of the room in the glass. 

But he couldn’t actively pay attention to both. 

Twilight or reflection had to give.  He termed the concept selective looking.”

Selective Listening

Our selective capacity is a blessing and a bane, and it applies across the senses.  It serves us when we want to focus, but at the expense of ignoring something else.

Knowing how this works can help us understand our strengths and weaknesses to more effectively direct our attention.

Konnikova writes:

“It was jut like selective listening – a phenomenon discovered in the 1950’s, in which people listening to a conversation with one ear would miss entirely something that was said in the other ear – except , on an apparently much broader scale, since it now applied to multiple senses, not just to a single one.

And ever since that initial discovery, it has been demonstrated over and over, with visuals as egregious as people in gorilla suits, clowns on unicycles, and even, in a real-life case, a dead deer in the road escaping altogether the notice of people who were staring directly at them.”

The Size of Your Pupils Say it All

The eyes are more than the windows to the soul.  They are windows into whether your attention and effort are waxing or waning.

The size of our pupils give us away.

Konnikova writes:

“Let’s go back to the sentence-verification task for a moment.  Not only will you have missed the proverbial twilight for focusing too intently at the reflection in the window, but the harder you were thinking, the more dilated your pupils will have become

I could probably tell your mental effort – as well as your memory lad, your ease with the task, your rate of calculation, and even the neural activity of your locus coeruleus (the only source in the brain of the neurotransmitter norepinephrine and an area implicated in memory retrieval, a variety of anxiety syndromes, and selective attentional processing), which will also tell me whether you are likely to keep going or to give up – just by looking at the size of your pupils.”

Checklists, Formulas, and Structured Procedures

How do we think like Sherlock Holmes on a more regular basis and prevent our Watson mind from taking over?

We have to force ourselves out of Watson mode and retrain our brains to think like Holmes using checklists, formulas, and structured procedures.

Konnikova writes:

“Daniel Kahneman argues repeatedly that System 1 – our Watson system – is hard to train.  It likes what it likes, it trusts what it trust, and that’s that. 

His solution?

Make System 2 – Holmes – do the work by taking System 1 forcibly out of the equation.  For instance, use a checklist of characteristics when hiring a candidate for a job instead of relying on your impression, an impression that, as you’ll recall, is formed within the first five minutes or less of meeting someone. 

Write a checklist of steps to follow when making a diagnosis of a problem, be it a sick patient, a broken car, writer’s block, or whatever it is you face in your daily life, instead of trying to do it by so-called instinct.  Checklists, formulas, structured procedures: those are your best bet – at least, according to Kahneman.”

Our Minds are Wired to Wander

Why is it so hard to pay attention?  Our minds are wired to wander.

Konnikova writes:

“It’s not necessarily our fault.  As neurologist Marcus Raichle learned after decades of looking at the brain, our minds are wired to wander.  Wandering is their default.  Whenever our thoughts are suspended between specific, discrete, goal-directed activities, the brain reverts to a so-called baseline, ‘resting’ state – but don’t let the word fool you, because the brain isn’t at rest at all. 

Instead, it experiences tonic activity in what’s now known as the DMN, the default mode network: the posterior cingulate cortex, the adjacent precuneus, and the medial prefrontal cortex

This baseline activation suggests that the brain is constantly gathering information from both the external world and our internal states, and what’s more, that is is monitoring that information for signs of something that is wroth its attention.  And while such a state of readiness could be useful from an evolutionary standpoint, allowing us to detect potential predators, to think abstractly and make future plans, it also signifies something else: our minds are made to wander. 

That is their resting state.  Anything more requires an act of conscious will.”

Attention is a Limited Resource

There’s only so much to go around.  We can’t pay attention to everything.  To pay attention to everything is to pay attention to nothing.

Konnikova writes:

“Attention is a limited resource.  Paying attention to one thing necessarily comes at the expense of another.  Letting your eyes get too taken in by all of the scientific equipment in the laboratory prevents you from noticing anything of significance about the man in that same room.  We cannot allocate our attention to multiple things at once and expect it to function at the same level as it would were we to focus on just one activity. 

Two tasks cannot possibly be in the attentional foreground at the same time. 

One will inevitably end up being the focus, and the other – or others – more akin to irrelevant noise, something to be filtered out.  Or worse still, none will have the focus and all will be, albeit slightly clearer, noise, but degrees of noise all the same.”

We See Less When We’re in a Bad Mood

You physically see less when you wake up on the wrong side of the bed.

Konnikova writes:

“We don’t even need to be actively engaged in a cognitively demanding task to let the world pass us by without so much as a realization of what we’re missing. 

For instance, when we are in a foul mood, we quite literally see less than when we are happy.  Our visual cortex actually takes in less information from the outside world. 

We could look at the exact same scene twice, once on a day that has been going well and once on a day that hasn’t, and we would notice less – and our brains would take in less – on the gloomy day.”

4 Ways to Pay Attention with Skill

Are we at the mercy of wherever our attention goes, or can we skillfully direct it?

According to Konnikova , we can direct our attention and improve our mindfulness like Sherlock Holmes, by doing four key things:

  1. Be Selective.
  2. Be Objective.
  3. Be Inclusive.
  4. Be Engaged.

Konnikova writes:

“Selectivity – mindful, thoughtful, smart selectivity – is the key first step to learning how to pay attention and make the most of your limited resources.  Start small; start manageable; start focused.  System Watson may take years to become more like System Holmes, and even then it may never get there completely, butt by being mindfully focused, it can sure get closer.”

5 Ways to Put it All Together

How do we put it all together and turn thinking like Sherlock Holmes into a repeatable system that we can use?

According to Konnikova , we can create a more effective, dynamic attic, if we put five key parts together:

  1. Know Yourself – and Your Environment
  2. Observe – Carefully and Thoughtfully
  3. Imagine – Remembering to Claim the Space You May Not Think You Need
  4. Deduce – Only from What You’ve Observed, and Nothing More
  5. Learn – From Your Failures Just as You Do from Your Successes

Beware the Rusted Razor Brain

Our brains get rusty from lack of use.  Use it or lose it.

Konnikova writes:

“Any time we get the urge to take it easy, we’d do well to bring to mind the image of the rusted razor blade from The Valley of Fear: ‘A long series of sterile weeks lay behind us, and here at last was a fitting object for those remarkable powers which, like all special gifts, become irksome to their owner when they are not in use.  That razor brain blunted with inaction.’ 

Picture that rusted, blunted razor, the yucky orange specks peeling off, the dirt and decay so palpable that you don’t even want to reach out to remove it from its place of neglect, and remember that even when everything seems wonderful and there are no major choices to be made or thoughts to be thought, the blade has to remain in use.  Exercising our minds even on the unimportant things will help keep them sharp for the important ones.”

If you want to take your thinking to the next level, Mastermind: How To Think Like Sherlock Holmes will help you do just that.

Get the Book

Mastermind: How To Think Like Sherlock Holmes, by Maria Konnikova is available on Amazon:

Mastermind: How To Think Like Sherlock Holmes, by Maria Konnikova

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  1. It sounds excellent. I wish it had a different title. For instance Holmes’ dictum that, ‘when what is possible has been eliminated what remains must be the truth’ doesn’t leave much room for imagination.

    • Great point on imagination.

      At work, I see debates between folks that use inductive reasoning, with those that prefer deductive. The inductive allows for more jumps and pattern-matching. Deductive is more linear. I’m a fan of making space for both.

      The good news is that Mastermind includes a lot of focus on creativity, imagination, and creative synthesis. It helps balance the methodical path.

  2. Konnikova seems not to have read Kuhn.

    There is no double blind randomly controlled trial that demonstrates that scientific thinking is better – and assuredly none that would guide us in our choice of values. We can as easily conduct experiments to increase the number of people we kill as to improving health.

  3. Very deep article indeed!Its for those persons like myself who have interest in mastering the self ,I have always been curious about characters like Mr Holmes who is exceptional in what they do so it would be a good opportunity to ready the book in its entirety.Thanks for sharing JD.

    • I think you’ll enjoy it deeply.

      It’s the kind of book that each time you read it, you appreciate it a little more.

      The way Konnikova serves up the science in a way we can use is well worth the price of admission.

    • Motivation is a powerful thing.

      Not only does it help focus and direct our attention, but I think what we want shapes our mindset, and our mindset shapes everything.

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