#28. A Summary of ‘Mastermind: How to Think Like Sherlock Holmes’ by Maria Konnikova

Mastermind: How to Think Like Sherlock Holmes by Maria Konnikova

Mastermind: How to Think Like Sherlock Holmes by Maria Konnikova (Viking Adult; January 3, 2013)

Table of Contents:

i. Introduction/Synopsis


1. The Two Modes of Thinking: The Watsonian Mode and the Holmesian Mode

2. The Holmesian Method as the Scientific Method in Action


3. A Robust and Well-Organized Knowledge-Base: Commandeering Memory-Formation

4. Maximizing Perceptiveness: Focused, Mindful and Objective Observation

  • a. Stay Focused

i. Cut out the Multitasking
ii. Be Selective: Goal-Directed Observation

  • b. Be Objective: Cut Out the Shortcuts and the Bias

i. Stereotyping
ii. Environmental Biases

  • c. Don’t Jump to Conclusions

5. A Lively (but Disciplined) Imagination

6. Incisive Deduction


7. Putting it All Together

8. Conclusion: When Holmesian Thinking Becomes Habitual

i. Introduction/Synopsis

Sir Arthur Conan Doyle’s character Sherlock Holmes is as popular today as when he was created back in the late 19th century. This comes as no surprise, of course, since there is just something about Holmes’ peculiar qualities—his keen observation, clever imagination, and incisive reasoning capabilities—that is both awe-inspiring and inspirational. We admire Holmes for cutting through the errors of thought that are so common to us in our daily lives (and that are reflected in Holmes’ sidekick, Watson). And yet we recognize that there is nothing in Holmes’ thought that is entirely out of reach for us. Indeed, his qualities are not so much superhuman as human plus: human qualities taken to their extreme. Still, human qualities taken to their extreme are intimidating enough, and we may find ourselves doubting whether we could ever really think like Sherlock—even if we put our minds to it. But for cognitive psychologist Maria Konnikova, we should think again.

Holmes’ prowess, Konnikova argues, rests no so much in his mental powers as in his mental approach. Specifically, Holmes has succeeded in making his thought methodical and systematic—essentially bringing the scientific method and scientific thinking to his detective work. This is an approach to thinking which, Konnikova argues, we can all learn. More importantly, it is an approach to thinking that can extend well beyond sleuthing. Indeed, it is a general approach that can help us get at the truth in virtually any matter, as well as help us solve virtually any problem. It is simply a matter of bringing a little science to the art of thinking—and it is this very thing that Konnikova aims to help us achieve in her new book Mastermind: How to Think like Sherlock Holmes.

Konnikova breaks down Holmes’ method into 4 parts: 1. Background knowledge; 2. Observation; 3. Imagination; and 4. Deduction. To begin with, Holmes keeps an extensive and well-organized knowledge base to help him solve new cases. What’s more, he is vigilant in ensuring that he is ever assimilating new and important information that could help him in the future. Second, Holmes uses careful, mindful, and unbiased observation to glean what is important about the various characters and circumstances of each case. Next, Holmes uses the evidence that he has gathered—in conjunction with his far-reaching (though disciplined) imagination—to formulate multiple scenarios that could explain the mystery. Finally, Holmes uses his acute powers of reasoning to cut away the scenarios that just don’t hold up, until ultimately there is but one scenario left: the only one that is possible, however improbable.

While this approach seems straightforward enough, it is easier said than done. Indeed, our minds can and often do go wrong at any one of the steps. Konnikova construes it like this: our minds have two distinct modes of thought. The first of these modes operates quickly and automatically. It is our default mode, in that it is the one that we rely on as a matter of course. While it may be quick and effortless, it is also very error-prone. Our second mode of thought is slower and more deliberate. It has the potential to be far more accurate than our default mode, but it takes effort, and this is effort that we often aren’t willing to expend. Still, Konnikova contends that activating the second mode is worth the effort. What’s more, the more we employ this second mode of thought, the more habitual and the less effortful it becomes. (These modes of thought correspond to System 1 and System 2 in Daniel Kahneman’s Thinking, Fast and Slow, though Konnikova refers to them here as our Watsonian and Holmesian systems).

At each step of Holmes’ method, Konnikova points out the errors of thought that our Watsonian system is want to draw us into (as exemplified by a series of psychological experiments). In addition, she points out numerous tricks and pointers that can help us use our Holmesian system to best advantage in order to overcome these errors (exemplified by still other psychological experiments). In the end, it is really a matter of being ever mindful and careful in our thinking, and this is something that we could all certainly do more of.

Here is Maria Konnikova discussing Sherlock Holmes and her new book:

What follows is a full executive summary of Mastermind: How to Think Like Sherlock Holmes by Maria Konnikova.


1. The Two Modes of Thinking: The Watsonian Mode and the Holmesian Mode

In order to get where we want in life we need an accurate picture of the world before us, as well as the ability to solve the problems that we face. Now, our minds naturally work at these things as a matter of course. Indeed, the brain is constantly surveying the environment, and forming quick impressions and judgements of what it takes in; which impressions and judgments influence our understanding and decisions (loc. 298-302). However, our brains are not always so rigorous in how they operate. Indeed, the mode of thinking that we normally work under is full of shortcuts and biases that often run at cross purposes to the goals we want to achieve (as we shall soon see). Ultimately, while this default mode of ours may be quick at forming impressions and judgments, and handles our day to day affairs well enough, it often sacrifices accuracy in the process—and this can lead to less than ideal results (loc. 305).

Now, it is certainly possible for us to go beyond this default mode of ours, and to be more conscious of how we engage with the world, and more rigorous in our thinking. In other words, in addition to our default mode of thought, we have access to a second mode of thinking with which to negotiate the world. As Konnikova explains, “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 auto pilot. The other is slower, more deliberative, more thorough, more logical—but also much more cognitively costly” (loc. 302).

While this second mode of thinking is slower and more effortful than our default mode, it has the potential to be far more accurate. Indeed, it is able to cut out the shortcuts and biases that plague our default mode, and so stands to yield great gains as a result. However, activating our second mode of thinking is not something that many of us do as much as we could (or should). The latter part of the quote above helps explain why: our second mode of thinking takes more effort than our default mode, and the simple fact of the matter is that we tend to be lazy. As Konnikova explains, “because of the mental cost of that cool, reflective system, we spend most of our thinking time in the hot, reflexive system, basically ensuring that our natural observer state takes on the color of that system: automatic, intuitive (and not always rightly so), reactionary, quick to judge” (loc. 305).

Also complicating the issue here is that we often don’t realize just how askew and error-prone our default mode of thinking is. That is, our default mode tends to allow us to get by well enough, thank you very much; and therefore, we may often see little reason to move beyond it. For Konnikova, though, when we look at the matter objectively, and weigh all the evidence, we should come to the conclusion that making more use of our second mode of thinking really is worth the effort. In fact, the author argues that we would do well to spend all of our time (or as much as possible) with mode two firmly in the ‘on’ position.

This may sound like a monumental effort indeed. However, Konnikova contends that it is not really so bad as it sounds. This proves to be the case since the more we make use of our second mode of thinking, the more habitual it becomes; until, finally, with enough practice, mode two becomes our default mode (loc. 295, 358-62, 3033). As the author explains, “just like a muscle that you never knew you had—one that suddenly begins to ache, then develop and bulk up as you begin to use it more and more in a new series of exercises—with practice your mind will see that the constant observation and never-ending scrutiny will become easier… It will become… second nature. You will begin to intuit, to deduce, to think as a matter of course, and you will find that you no longer have to give it much conscious effort” (loc. 365).

It is this, effectively, that Sherlock Holmes has been able to do: thinking in mode two has become second nature to him (loc. 365). Watson, on the other hand, remains firmly rooted in mode one (loc. 307). Of course, both Holmes and Watson are fictional characters; however, we should in no way conclude from this that they are unbelievable, or that Holmes’ methods are unattainable. Indeed, to begin with, Conan Doyle based his Sherlock Holmes on a real-life acquaintance. As Konnikova explains, Holmes’ “character… was modeled after another mentor, Dr. Joseph Bell, a surgeon known for his powers of close observation” (loc. 215).

The following is a very good documentary about Dr. Joseph Bell, the inspiration behind Sir Arthur Conan Doyle’s Sherlock Holmes:

And regardless, Konnikova insists that what holds for Holmes and Watson (fictional though they may be) holds for us as well. In other words, while all of us are equipped with both modes of thinking, one or the other will dominate in each of us; and it is up to us to decide which one it will be.

Since Watson remains stuck in the original default mode of thinking, while Holmes has managed to elevate himself to mode two, Konnikova refers to the different modes of thinking as Watsonian and Holmesian respectively (loc. 308) (readers of Daniel Kahneman’s Thinking, Fast and Slow will recognize the Watsonian and Holmesian modes described here as System 1, and System 2 (loc. 1178). Those interested in pursuing this topic further may be interested in my Summary of Thinking, Fast and Slow).

Now, when we take rigorous, methodical and rational thinking to its extreme, this is really nothing more nor less than the scientific method in action (loc. 210). And indeed, when Conan Doyle created Sherlock Holmes, this is precisely what he had in mind. As Konnikova explains, “In Arthur Conan Doyle’s own estimation, Sherlock Holmes was meant from the onset to be an embodiment of the scientific, an ideal that we could aspire to” (loc. 211; see also 198-229). Elsewhere, Konnikova writes that “what Sherlock Holmes offers isn’t just a way of solving crime. It is an entire way of thinking, a mindset that can be applied to countless enterprises far removed from the foggy streets of the London underworld. It is an approach born out of the scientific method that transcends science and crime both and can serve as a model for thinking, a way of being, even, just as powerful in our time as it was in Conan Doyle’s” (loc. 198).

Given that Holmes’ approach is based on the scientific method, then, before we turn our attention specifically to Holmes’ approach, it will help to get a brief refresher of the scientific method.

2. The Holmesian Method as the Scientific Method in Action

The scientific method is very simple really. Here it is in plain terms: “make some observations about a phenomenon; create a hypothesis to explain those observations; design an experiment to test the hypothesis; run the experiment; see if the results match your expectations; rework your hypothesis if you must; lather, rinse, and repeat” (loc. 278).

*For prospective buyers: To get a good indication of how this (and other) articles look before purchasing, I’ve made several of my past articles available for free. Each of my articles follows the same form and is similar in length (15-20 pages). The free articles are available here: Free Articles

6 thoughts on “#28. A Summary of ‘Mastermind: How to Think Like Sherlock Holmes’ by Maria Konnikova

  1. Hello! This book seems to be very inspired by Daniel Kahneman’s book “Thinking, Fast and Slow”….and I’m curious if it would be worthwhile to read that book as well – the reason I ask, is because, while I have no doubt that book would be very informative and expand my understanding of the mind…I’m seeking a more practical effect, like the type this book aims for — not simply to better understand why we make our decisions, but what we would to improve them in our everyday lives…it’s why this book here by Maria Konnikova intrigues me; it apparently attempts to teach what you could do, and that sort of practical effect is what I’m aiming for.

    Thank you very much; your website is an extremely informative “sneak-peek” at many books before I actually read them….it helps to make my decision whether I should get them.


    • I would also like to ask if their are any other books you would recommend, like these, that could be used as self-help guides in order to become a more capable thinker. As before, more then simply learning more about the inner-workings of the mind, I want to be able to leverage the research in order to sharpen my own thinking in a practical way.

      • Hey Gabriel. As far as recommendations go, I’m afraid I can’t do much better than ‘Mastermind’ and ‘Thinking, Fast and Slow.’ I don’t really do a lot of self-help books, so I’m really not much of an authority here. Having said that, there was a book released recently that seems to capture just what you’re after. It’s called ‘Super Brain: Unleashing the Explosive Power of Your Mind to Maximize Health, Happiness, and Spiritual Well-Being’ by Deepak Chopra. I haven’t read it, though, so I can’t vouch for it, but you may want to check it out.


    • Hi Gabriel. Thanks for your note, I’m glad you like the site. You’re right, this book is in many ways very similar to Kahneman’s ‘Thinking, Fast and Slow.’ The main difference is that Kahneman focuses more on the follies of System 1 (the Watsonian mode in Konnikova’s book), while Konnikova focuses more on how we can discipline our thinking and make it more Holmesian (System 2 in Kahneman’s book). In this sense it may seem like Konnikova’s book is more practical, but I’m not sure I would say this is so. Just knowing the many ways that System 1 can lead us astray, and how it does so (which Kahneman does much better than Konnikova) can go a long way towards helping us overcome it. I would certainly say that Kahneman’s book is worth reading (you may have noticed that I have written a summary of ‘Thinking, Fast and Slow’, so you can always start there). Anyway, hope that helps.


  2. Thanks for this very accurate summary !
    It is much more efficient to apply the content than the book itself. (I had read the book before)

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