Magic tricks can teach us about how the brain works. Magic capitalises on very specific blind spots in people’s attention and perception so the techniques that magicians use to trick audiences are particularly interesting to psychologists like me.
Misdirection, for example, relies on the control of the audience’s attention to fool them. A magician will divert the audience’s attention away from things that show how the trick is done, towards the effect they want them to see. This and other magic techniques can reveal important characteristics of how our minds work.
But magic tricks might also be a good tool to investigate the non-human animal mind. The study of how animals perceive magic effects that fool and surprise humans can help us understand how their minds experience the world around them, and whether such experiences are in some way like ours.
That’s why, in a recent study, my colleagues and I tried to perform magic tricks to birds. We tested sleight of hand on Eurasian jays, and found they were fooled by some tricks and not by others.
Misdirection is not totally new to some birds. Corvids – large-brained birds in the crow family including jays, ravens and magpies – hide food they can retrieve later, a behaviour known as caching. But if another corvid is watching them hide the food, they run the risk of their cache being stolen.
To get around this, this clever family of birds use intricate and highly elaborate protection tactics that are comparable to the misdirection used by magicians. For example, corvids can hide food discreetly in one spot while pretending to hide it in many other places, making it difficult for the observer to spot the real cache.
In our study, we performed three different sleight of hand tricks to six Eurasian jays and 80 human participants. Known as palming, French drop and fast pass, they are all used in magic routines to make objects appear and disappear.
Palming involves hiding an object in your palm while pretending the hand is empty. The French drop – shown in the gif below – involves pretending to pass something from one palm to the other, without actually moving the object. Finally, the fast pass involves moving an object between your hands so quickly it’s not seen by the audience.
They all involve misleading the observer into thinking an object has or hasn’t been transferred from one hand to the other.
For the first two of these tricks – palming and French drop – to succeed in misleading the average audience member, the observer needs some inherent understanding of what a typical transfer of objects entails. It’s this knowledge that certain movements usually produce particular outcomes that leads a spectator into assuming there was no foul play.
Little is known about corvids’ preconceptions of human hand motions or whether they have similar expectations as us when observing transfers of objects between hands. Birds don’t have hands, so we wanted to find out whether they understand what hand movements should mean.
The third sleight of hand effect we used doesn’t rely on such expectations. Fast pass is based on the magician’s ability to performed very fast motions, which aren’t usually perceived by the observer.
Birds have different visual perception than people, with a much wider field of view. If our jays fell for similar sleight of hand techniques that magicians use to deceive humans, it might mean that they had similar blind spots.
Unlike our human sample, which was significantly fooled by all three of the magic effects we performed, Eurasian jays didn’t seem to be fooled by the first two tricks. This could be because jays lack the expectations about hand mechanics that makes us humans liable to these techniques of deception.
But our sample of jays was significantly fooled by the third technique – as shown in the gif below – suggesting that their visual system can be exploited with similar methodologies as the ones used in humans.
It is possible that the effect might be exploiting different blind spots in attention and perception to those in people. Further research should be conducted to fully investigate the blind spots, and whether these are similar to our perceptive failures or explained by something else.