I often find myself walking into the kitchen (or the living room or bedroom or wherever), unable to recall why I was going there in the first place. What I do in those cases is retrace my steps, until I am back to where I began my trip. And more often than not, the location triggers the precise association that prompted me to move in the first place, and I triumphantly return to the place of forgetfulness, ready to do whatever it is that needs doing.

In this case, I'm exploiting the close contextual nature of memory: our minds respond to cues in our surroundings to retrieve whatever it was that needed retrieving. In other words, we recall information better in the same environment as we stored it--or, in my case, the same environment that triggered the connection--to begin with. Context, in all its forms--visual, aural, olfactory, tactile--works as an essential memory cue.

But can the connection go the other way around? Can a specific environment help trigger thoughts and associations that weren't already there to begin with? That, in essence, is the suggestion that Holmes makes to Watson in The Valley of Fear, when he proposes to return to the scene of the crime under investigation in the evening.

“An evening alone!” Watson exclaims. Surely, that would be more morbid than anything else? Nonsense, Holmes counters. It could actually be quite illustrative. “I propose to go up there presently. I have arranged it with the estimable Ames, who is by no means whole-hearted about Barker. I shall sit in that room and see if its atmosphere brings me inspiration. I'm a believer in the genius loci. You smile, Friend Watson. Well, we shall see.” And with that, Holmes is off to the study.

And does he find inspiration? Indeed he does. And the next morning, he is ready with his solution to the mystery.

How a change in location can signal a change in perspective

But did Holmes really think that he could recreate events by being in the room where they took place, without the prior knowledge necessary to trigger such contextual memories? Hardly. Instead, he was doing something which is absolutely essential in the proper exercise of deduction and thought: taking the perspective of those involved in the crime instead of proceeding purely from his own vantage point. And in that sense, location is indeed a powerful ally.

Perspective-taking is an essential part of interacting with the world: we need to be able to see things from others' perspectives in order to understand them and interact with them. Indeed, the ability to take another's point of view is a crucial early developmental step in the formation of Theory of Mind, one of the areas where individuals who suffer from autism are most lacking. But perspective-taking goes beyond the fundamental ability to realize that others don't always see the same thing we ourselves see--even though unfortunately, for many people, it stops at precisely that point. We are not often trained to look at the world from another's point of view in a more basic, broad fashion that transcends simple interaction. How might someone else interpret a situation differently from us? How might he act given a specific set of circumstances? What might he think given certain inputs? These are not questions we often find ourselves asking.

Indeed, so poorly trained are we at actually taking someone else's point of view that when we are explicitly requested to do so, we still proceed from an egocentric place. In one series of studies, researchers found that people adopt the perspective of others by simply adjusting from their own. It's a question of degree rather than type: we tend to begin with our own view as an anchoring point, and then adjust slightly in one direction, instead of altering the view altogether. Moreover, once we reach a satisfactory-sounding estimate, we stop thinking and consider the problem resolved. We've successfully captured the required point of view. That tendency is known as satisficing: a response bias that errs on the egocentric side of plausible answers to a given question. It's especially strong when a plausible answer is presented early on in the search process--we then tend to consider our task complete, even if it's far from being so.

And, the busier we are and the more pressured, the less accurate--and what is a police investigation but a time-sensitive pressure-cooker, with the weight of expected quick results on the shoulders of the investigators and a variety of plausible-sounding options that are all too tempting to grasp at awaiting analysis? And that, in essence, is what Holmes's genius loci technique is aimed at avoiding. Holmes realizes both the necessity of getting into the mindset of the actors involved in the drama and the immediate difficulty of doing so, with all of the elements that could at any point go wrong. And what better way to push all distracting information to the side and focus on the most basic particulars, in a way that is most likely to recall that of the original actors, then to request a solitary evening in the room of the crime? Of course, Holmes still needs all of his observational and imaginative skills once he is there - but he now has access to the tableau and elements that presented themselves to whoever was present at the original scene of the crime. And from there, he can proceed on a much more sure footing.

Indeed, it is in that room that he first notices a single dumbbell, surmising at once that the missing member of the pair must have somehow been involved in the unfolding events, and from that room that he deduces the most likely location of the dumbbell's pair: out the only window from which it could reasonably have been dropped. And when he emerges from the study, he has changed his mind from his original conjectures as to the proper course of events: while there, he was better able to get into the mindset of the actors in question, and in so doing, clarify the elements that had previously been hazy.

And in that sense, Sherlock Holmes actually does invoke the same contextual memory principle as I explored earlier in the piece, except instead of using context to cue memory, he uses it to cue perspective-taking and imagination. Given this specific room, at this specific time of day, what would someone who was committing or had just committed the crime in question be most likely to do or think?

Perspective-taking is a tremendously difficult endeavor. It is far simpler to use yourself as the prototypical actor, often without realizing you're doing so, instead of separating yourself entirely from the exercise. But it is nevertheless an essential skill. And so, we must use every possible tool at our disposal to improve our ability to see the world from a vantage point that isn't our own; and as Holmes demonstrates, one such tool is as simple as a change of location--and if that location is the same as that of your target perspective, so much the better.

Photo credit: Groombridge Place in Tunbridge Wells in the county of Kent, the original setting for The Valley of Fear. Copyright Francois Thomas and licensed for reuse under this Creative Commons License.