Free Mastermind: How to Think Like Sherlock Holmes by Maria Konnikova

perception of a person, even if every other descriptive point remains the same. And that first impression will last, just as Watson’s captivation with Miss Morstan’s hair, eyes, and dress will continue to color his evaluation of her as a human being and his perception of what she is and is not capable of doing. We like being consistent and we don’t like being wrong. And so, our initial impressions tend to hold an outsized impact, no matter the evidence that may follow.
    What about Holmes? Once Mary leaves and Watson exclaims, “What a very attractive woman!” Holmes’s response is simple: “Is she? I did notobserve.” And thereafter follows his admonition to be careful lest personal qualities overtake your judgment.
    Does Holmes mean, literally, that he did not observe? Quite the contrary. He observed all of the same physical details as did Watson, and likely far more to boot. What he didn’t do was make Watson’s judgment: that she is a very attractive woman. In that statement, Watson has gone from objective observation to subjective opinion, imbuing physical facts with emotional qualities. That is precisely what Holmes warns against. Holmes may even acknowledge the objective nature of her attractiveness (though if you’ll recall, Watson begins by saying that Mary’s has “neither regularity of feature nor beauty of complexion”), but he diregards the observation as irrelevant in almost the same breath as he perceives it.
    Holmes and Watson don’t just differ in the stuff of their attics—in one attic, the furniture acquired by a detective and self-proclaimed loner, who loves music and opera, pipe smoking and indoor target practice, esoteric works on chemistry and renaissance architecture; in the other, that of a war surgeon and self-proclaimed womanizer, who loves a hearty dinner and a pleasant evening out—but in the way their minds organize that furniture to begin with. Holmes knows the biases of his attic like the back of his hand, or the strings of his violin. He knows that if he focuses on a pleasant feeling, he will drop his guard. He knows that if he lets an incidental physical feature get to him, he will run the risk of losing objectivity in the rest of his observation. He knows that if he comes too quickly to a judgment, he will miss much of the evidence against it and pay more attention to the elements that are in its favor. And he knows how strong the pull to act according to a prejudgment will be.
    And so he chooses to be selective with those elements that he allows inside his head to begin with. That means with both the furniture that exists already and the potential furniture that is vying to get past the hippocampal gateway and make its way into long-term storage. For we should never forget that any experience, any aspect of the world to which we bring our attention is a future memory ready to be made, a new piece of furniture, a new picture to be added to the file, a new element to fit in to our already crowded attics. We can’t stop our minds from forming basic judgments. We can’t control every piece of information that we retain.But we can know more about the filters that generally guard our attic’s entrance and use our motivation to attend more to the things that matter for our goals—and give less weight to those that don’t.
    Holmes is not an automaton, as the hurt Watson calls him when he fails to share his enthusiasm for Mary. (He, too, will one day call a woman remarkable—Irene Adler. But only after she has bested him in a battle of wits, showing herself to be a more formidable opponent, male or female, than he has ever encountered.) He simply understands that everything is part of a package and could just as well stem from character as from circumstance, irrespective of valence—and he knows that attic space is precious and that we should think carefully about what we add to the boxes that line our minds.
    Let’s go back to Joe or Jane Stranger. How might the encounter