What Pickpockets Know and Your Brain Would Rather Not Tell You

Be under no illusion.  You saw the sign: “Pickpockets are operating in this area”.  You reacted.  Instantly.  The first thing you did was to check your pockets or handbag for signs of financial solvability.  All is well.  You relax.  Only now, you’ve become the “mark”… because you’ve just given away precious information about the location of your valuables around your body. 

According to neuroscientists, our brains come pretty much hard-wired to be tricked, all thanks to the vagaries of our attention and perception systems.  Indeed, the key requirement for a successful pickpocket is not so much having swift fingers, as it is having a practical knowledge of the loopholes in our brains.  Some are so proficient at it that researchers have been working with them to get an insight into the way our minds work…

 

“Look Into The Eyes, Not Around The Eyes…”

Visual illusions developed by painters and sculptors have aided the understanding of important principles of visual perception.  Likewise, cognitive illusions developed by magicians can reveal critical clues in cognitive processing.

Centuries of informal but systematic research in magic theory have predated contemporary cognitive science concepts such as:

• “change blindness” (Simons and Levin, 1998),
• “inattentional blindness” (Simons and Chabris, 1999), and
• “choice blindness” (Johansson et al., 2005).

Magic and illusionism remain a rich and largely untapped source of insight into perception and cognition as in The Exploitation of Gestalt Principles by Magician (Barnhart, 2010).  The paper notably highlights two co-occurring principles that appear to form the basis of many popular magic tricks: accidental alignment and good continuation.

 

The Gentleman Thief

One of the study’s authors – Las Vegas stage pickpocket Apollo Robbins aka The Gentleman Thief – is a professional magician who specialises in sleight of hand and stage pickpocketing.  Robbins noticed that he could direct a spectator’s attention in distinctive ways by moving his hands along different trajectories, for instance, while secretly stealing an object from his “mark” or victim.

 

Specifically, Robbins moves his hands in a curved motion to engage the spectator’s attention along the motion trajectory.  And he uses linear motion to shift attention from the start to the end point of a vector.

Both types of movements decrease the attentional focus at the onset position of the hand movement, but with curvilinear motion the shift towards the final position is more permanent.

 

Tricks of the Mind

The most significant of our brain’s loop-holes is the fact that our brains are not built for multi-tasking.  Most of the time, that is a good thing.  It lets us filter out all but the most important features of the World around us.  Tricksters and magicians exploit a whole range of psychological principles in deceiving their audiences.

• The French Drop is a classic sleight of hand magic trick, with the following sequence:

(a) The magician shows a coin or another small object between the fingers and thumb of one hand (i.e., left hand).

(b) The right hand approaches the left hand and appears to take the coin.

(c) The right hand moves away from the left hand as if carrying the coin; and

(d) The magician opens his right hand to reveal that the coin has disappeared.

 

This simulated manoeuvre results in the perception that the coin has magically vanished from the right hand (when in reality, it was not removed from the left hand).  Step (c) of the French Drop can be performed using either curved or straight hand motion.

Although the illusion is effective either way, Apollo Robbins successfully predicted that straight motion should result in the spectator’s gaze bouncing from the open right hand back to the closed left hand (which retained the hidden coin) immediately after the reveal, whereas curved motion would cause the spectator’s gaze to remain focused on the final hand, rather than returning to the original hand.

 

The scientists tracked the eye movements of naïve subjects, as they viewed videos of Robbins executing the French Drop with linear versus curved motion.

As predicted by Apollo Robbins, subjects showed different eye movement patterns for the two types of motion.  The spectators’ gaze stayed on the right hand more often after the curved motion, whereas it jumped back to the left hand after the straight motion.  Thus, magicians manipulate not only the audience’s gaze position during a sleight, but also the subsequent gaze location, once the sleight is complete.

 

How Your Brain Deceives You

Say I want you to stop looking at something on the table, it is much easier for me to give you a good reason to look elsewhere.  If I can manage to give you two or maybe three things to focus on, and the one I want you to avoid is not one of them, that is even better because now I have given you the illusion of choice.

Generally, people think it is about distracting someone by making them look away, but it is actually about directing the mind towards something.  While sleight of hand may help achieving this result, it is as much about capturing all of somebody’s attention with other movements.  Street pickpockets use this effect to their advantage by manufacturing a situation that cannot help but overload your attention system.

• A classic trick of the pick-pocketing trade is the ‘Stall’, used by gangs over the World. 

First, a ‘blocker’, walks in front of the victim (or ‘mark’) and suddenly stops so that the mark bumps into them.

Another gang member will be close behind, who then bumps into both of them, and starts arguing with the blocker.

Amid the confusion, one or both of them steal the victim what they can and pass it onto a third member, who makes off with the loot.

Tactics are psychological for very good reasons.  Pickpockets tend to hang out near ‘beware of pickpockets’ signs, because the first thing people do when they read it, is check they still have their valuable belongings, helpfully giving away where they are.

 

Making a Smart Move

Specific movements can also trick us.  Moving your hand through the air in a straight line between two points, is less effective at holding people’s attention on the end point than moving your hand in an arc motion.  An arc motion makes people’s gaze stick to the curving hand and stay there, while a straight line makes their eyes flick back to the beginning and jump between the two.

Sure enough, eye-tracking experiments showed that this was correct.  But why?

Apparently, it is all down to the way different movements engage the visual system.  Following an arc uses an eye movement called ‘smooth pursuit’, where the eye continuously follows an object.  A straight line makes the eye move in a ‘saccade’ – a fast movement where the eye moves from point A to point B in a fraction of a second.

Illusions developed by magicians and con artists remain a rich and largely untapped source of insight into perception and cognition.  What Otero-Millan et al. (2011) have demonstrated here is that curved motion, as employed by the magician in a classic sleight of hand trick, generates a much stronger misdirection than rectilinear motion, and that this difference can be explained by the differential engagement of the smooth pursuit and the saccadic oculo-motor systems.

If the research proves true, the use of curved hand motions in certain magic routines may help to disrupt the “reconstruction process” – the ability of the spectator to reconstruct the trick after the performance, or to determine the secret method and link it to the intended magical effect. 

The research exemplifies how the magician’s intuitive understanding of the spectator’s mindset can surpass that of the cognitive scientist in specific instances.  And it shows that observation-based behavioural insights developed by magicians are worthy of quantitative investigation in the neuroscience laboratory.