Although we insist on not expressing our emotions, the pupils reveal part of what we feel or the mental effort we make

Our looks reveal something more than enjoyment or attraction, like the mental effort in which we are immersed.

There is a subtle but perceptible part that reveals whether we like something or whether it horrifies us. As much as we try to hide our emotions, the body gives us away. Our pupils do it, capable of increasing up to 30 times their size when they notice a stimulus. In this way, we express our pleasure, but also our mental effort. You can observe it for yourself. Ask someone to see a series of images that you have previously chosen. Show them slowly and get close enough until you can see the reaction in their eyes. Include in the selection pleasant stamps and others that are not so pleasant. If your pupils dilate, it means that you like what you see at that moment. It will be something subtle, but testable.

The rest of the body may seem immovable, but our pupils leave us in evidence (be careful, the previous exercise can be high risk if you do it with a partner and with somewhat compromising images). The love tandem between pleasure and dilation of the pupils was described by the psychologist Eckardt Hess in an article published in 1964 . However, knowledge of this tandem is ancient, as the author explains. For example, those who shop at bazaars professionally know that they are more effective if they negotiate prices while wearing sunglasses. That way, the salesperson can’t see your eyes and doesn’t really know if you like the product. Buyers can thus have a greater margin of maneuver when negotiating the price. The language of our pupils not only expresses what we feel. It goes further: it is also a magnet for looks.

Hess included two nearly identical images of beautiful women in his article. There was only one small variation between them: their eyes. Curiously, the ones that were most seductive to most observers were the ones in which the models’ pupils were larger and sparkled. The explanation seems to have an evolutionary origin: a person with dilated pupils is more attractive because they can be more available (we are not talking about the forced dilation to analyze the eye, but about the discreet one). This fact has been known since ancient times. In Rome, for example, women used the atropa belladonna plant (“beautiful woman” in Italian) as a cosmetic product, capable of enlarging the pupils. But our looks reveal something more than enjoyment or attraction, like the mental effort in which we are immersed.

Jackson Beatty, an eminence in the study of cognitive pupillometry , conducted several experiments in which he asked participants to perform various mathematical equations. He found that when we perform operations of two or three digits, our pupils dilate up to 50% more during the first five seconds. In other words, intellectual work supposes an inner activation that also has its expression outwards, and not only in our eyes, but also in our hearts. The palpitations increase: seven more per minute on average. The discovery between the intellectual effort and pupil tandem opened a line of research to verify if we think in an elaborate way or if we have put the automatic pilot. In short, our body speaks for itself. Although we strive not to express our emotions, the pupils reveal part of what we feel, or the mental effort we make. Thus, our gaze is one more reason to be consistent with what we say .