Anticipating the actions of another member of the species is a very useful skill for social animals like humans. Thanks to this anticipation we can coordinate our actions; some simple like a high five, or others more complicated like dancing a tango. Magicians and conjurers take advantage of these anticipations that we make practically instantly to surprise their audience. His tricks, tricks and tricks use movements and situations in which the audience forms an outcome in their minds, but, in a final script twist, the result that seemed obvious does not occur, but something unexpected happens and, therefore, surprising.
doing science with magic
It is curious to say the least that an article in a science section talks about magic, but the reason is that this practice is a rather novel approach to understanding how animals relate to the world around them. Performing magic tricks on dogs, cats and even non-human primates allows us to delve into the pathways their brain uses to process the information that reaches them. And this is precisely the experimentation premise of Dr. Elías García-Pelegrín, from the Comparative Cognition Laboratory of the University of Cambridge. In an article published in the magazine Current BiologyDr. Gracía-Pelegrín has compared the reactions of different primates to a trick called “French Drop” or French Fall.
The French Drop is one of the first moves to be taught when wanting to learn the art of sleight of hand. It consists of imitating the transfer of objects from hand to hand by means of a deception that simulates the grip of said object. This grip is done partially hidden from view, so the magician can drop said object into the palm of his hand. Thus, when the spectator thinks that the object is in the hand that has grabbed it, it really is not like that, but rather that it is resting in the hand in which it was initially found. The key for this movement to work is in the thumb, which is in charge of grabbing -or not- the object.
There is no trick without a thumb
The species chosen for the experiment were different physiognomically different platyrrhines among them: the common marmoset (Callithrix jacchus), Humboldt’s squirrel monkey (saimiri cassiquiarensis) and the yellow-breasted capuchin (Sapajus xanthosternos). After performing magic tricks on the different species, they observed a very curious pattern. capuchins, and squirrel monkeys having, respectively, fully and partially opposable thumbs, they react like the humans before a trick that involves the use of the thumb as a causative agent. In other words, they would also expect the coin to have changed hands during the trick and are surprised when this is not the case. However, this reaction does not occur with marmosets, whose thumbs are not opposable.
In this experiment, various parameters were taken into account so that the results could be as robust as possible. Thus, Primates were chosen from zoos in which contact with animals humans was minimal. In this way, it can be ruled out that the monkeys have learned how the biomechanics of the human hand works by observing it, but that only have their own hands and those of other members of their species as a reference. This was not possible in the case of the marmosets, since they were animals from a research center, but even so, these monkeys did not “fall for the trick.”
Creating magic for monkeys
Subsequently, to rule out that it was really that the primates were not capable of waiting for the result, they created a version of the French Fall that did not require the thumb. The variant uses a “power grip”, which can be performed by all platirrinos, and this adapted version of the trick was able to fool all three species of monkeysregardless of the anatomy of your hands. Therefore, the research shows the strong interaction between one’s own physical ability to perform an action and the predictions that can be made of the result of the action in other individuals of a different species.
There is still a lot of research in this regard to understand what neural mechanisms are responsible for these behaviors and how they affect social relationships. However, research such as this offers robust evidence that an observer’s abilities influence how he relates to his environment and how he is able to predict the movements of other animals in his environment.
DON’T GET IT:
Squirrel monkeys have partially opposable thumbs and cannot perform a precision grip with it. However, the researchers believe that they are capable of understanding that such a grasp can be done because they can replicate the movement to grasp larger objects.
REFERENCES (MLA):
Clayton, N. Manual action expectation and biomechanical ability in three species of New World monkey. Current Biology https://doi.org/10.17863/CAM.95030
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