Whenever I teach my undergraduate course, “Psychological Sleuthing,” I open with a Sherlock Holmes story. This popular character demonstrates the importance of keen observation, careful reasoning, and a hypothesis that avoids tunnel vision. It’s an important foundation to help students think not just outside the box but also to think well, based on awareness and evidence.

I always point to Joseph Bell, a Scottish surgeon and mentor of Holmes’ creator Arthur Conan Doyle, who invented “the Method.” As Bell described it, this was a disciplined approach to deducing subtle facts about his patients from nothing more than keen observation. The successful diagnosis, he believed, derived from three things: “Observe carefully, deduce shrewdly, and confirm with evidence.”

I hope to impart a sense of the importance of these activities, because many of my students will become police officers, attorneys, analysts, federal agents, and psychologists.

Thus, I was delighted to learn about Maria Konnikova’s new book, Mastermind: How to Think Like Sherlock Holmes (Viking). Konnikova, a psychologist and journalist, writes a column, “Literally Psyched,” for Scientific American. She’s a fan of the Holmes tales and she takes seriously his metaphor of the “brain attic.”

In fact, she goes well beyond anything that Conan Doyle might have known in his day to illuminate Holmesian concepts with research from cognitive and neuropsychology.

However, this is no inaccessible guide to science. Konnikova’s point is to use the sophistication of science to demonstrate how, with a bit of and discipline, we can all learn to “think like Sherlock Holmes.”

What characterizes Holmes is a “natural skepticism and inquisitiveness toward the world.” More than this, however, Holmes remains ever mindful of typical errors of thinking, such as biases, and he constantly scans for ways to solve what seems unsolvable. He doesn’t give up.

Thankfully, there is no attempt in this book, as we’ve seen in recent television series, to set Holmes apart and explain his avoidance of the emotional brain as a “condition” like ’s disorder. Holmes has a practiced state of disciplined , with the goal of accuracy and efficiency. The point is not that he’s “different.” The point is that he’s worked hard to hone his ability to see and think, and so can we. It’s a matter of resisting the mind’s natural tendency to follow the path of least resistance.

“A fool takes in all the lumber of every sort that he comes across,” Holmes says to Watson, “so that the knowledge which might be useful to him gets crowded out…so that he has difficulty in laying his hands on it. Now the skillful workman is very careful indeed as to what he takes into his brain attic.”

Posing the limited, diffuse mindset of Dr. Watson against the fluid, growth-empowering, can-do mindset of Holmes, Konnikova addresses how mental laziness steers us away from the hard work of examination and reasoning. Our minds are made to wander, she states, and we prefer to let them go. Multi-tasking only exacerbates this tendency. But this is no way to think like Sherlock Holmes.

If we want his powers of perception and , we need the two Ms: mindfulness and , along with a good dose of imagination. Think ahead, clarify your end point, be prepared for options, and develop an effective distancing device.

The chapter on observation deconstructs the difference between Watson (representing us) and Holmes. The comparison shows us the steps that Holmes has taken to be able to see in a glance an abundance of information about someone he has never met. We learn about such things as the , functional fixedness, and satisficing. We also gain the tools to overcome these mental stumbling blocks.

I particularly appreciated the chapter that shows how Holmes’ thinking process is not necessarily linear, as most of us believe. Having researched the importance of relaxing the mind in order to fuel a eureka insight that explodes a mental impasse, I enjoyed seeing examples of Holmes’ use of this device.

His habits are perfectly suited for flashes of illumination. He builds a knowledge base of items that he believes will be most helpful in his work, relaxes by playing the violin or a pipe, and lets his brain scan through the data of a specific case until voila! It all comes together.

In the end, Konnikova offers a guiding reminder. “If you get only one thing out of this book,” she says, “it should be this: the most powerful mind is the quiet mind. It is the mind that is present, reflective, mindful of its thoughts and its state. It doesn’t often multi-task, and when it does, it does so with a purpose.”

As I was reading, I was aware of how important these insights are for criminal investigations. In fact, Kim Rossmo made a study of how cognitive errors specifically affect investigations. In Criminal Investigative Failures, he mentioned many of the same items. He discusses how investigators typically arrive at scenes with a perceptual set. These mindsets help them decide what to do next, but they can become problematic if decisions are premature or too entrenched in a specific idea.

Like Konnikova, Rossmo points out that clear and rational thinking is not automatic and “our brains are not wired to deal effectively with uncertainty.” Problems with evidence can result from hasty, incomplete, or biased interpretation – the same errors that Watson makes in the Holmes stories.

I’ve been using insights from Holmes for a while, and I appreciate the organized articulation in Mastermind of how any of us can train our brains to emulate the iconic consulting detective.