You probably haven’t noticed this, but throughout the history of art, portrait models don’t smile. There are very few works that you will find with a subject smiling. This happens because at some point the smile had negative connotations. In the mid-seventeenth century it was believed that smiling was a vulgar and inappropriate gesture, generally associated with madmen, jesters, perverts, drunks, and prostitutes. However, Leonardo da Vinci was one of the pioneers in leaving behind this belief and inspired dozens of artists to follow his footsteps. Although the artist has created few portraits, the small, almost imperceptible smile he included on his models was a barrier he broke over the rules of portraiture. His most notorious work, “Mona Lisa” (1503), is a clear reflection of the enigmatic smile.
Author of the most famous works of art, Leonardo da Vinci represented the ideal of the humanist man of the Renaissance. Not only was he a sublime artist, but he was also a man of thought. Da Vinci spoke several languages, including Greek and Latin. He had a vast knowledge of various fields including architecture, geography, mechanics, mathematics, astronomy, optics, cartography, and even botany. But above all, the artist had an extraordinary ability to observe reality in depth and draw with absolute precision. According to his own writings, he spent time rigorously observing and dissecting corpses. This allowed him to acquire knowledge in anatomy that he later applied to his paintings.
Although his production was not very extensive, Leonardo Da Vinci left great contributions to the history of art. Among them, the creation of the sfumato technique, the classic symmetry of his compositions, the rigor for detail and realism, the golden perspective, and the study of proportions. Thanks to this, he forms part, together with Michelangelo and Raphael, of the holy trinity of Renaissance art, as stated by the historian Vasari. But one of his most revolutionary contributions was the inclusion of the smile in the portraits, which in turn, represents one of the greatest enigmas in the history of art until now.
The Mona Lisa’s shy smile and the intriguing look is one of the most characteristic elements of the work. The effect that Da Vinci had applied generated an optical illusion that sparked a great debate for centuries about whether she was smiling or not. This was due to the ambiguity conveyed by the woman’s face that a full smile could not. The half-smile that does not accompany the rest of the gesture and the serious features of the model makes the viewer perceive different expressions. It is capable of generating interest, condescension, flirtation, longing, boredom, joy, or shame. Specialists have come to call it “the unattainable smile”.
Over time, countless wild theories have emerged about the true meaning of the Mona Lisa’s smile. In fact, there are investigations that achieved a lot of repercussions that assure that the gesture is the artist’s creation, that is to say, that the model was not really smiling. The main argument is that the woman had to have been smiling for hours and this would have caused her strong muscular pain. Therefore, it is most likely that the artist added the smile. But also, a study from the University of Cincinnati shows that the Mona Lisa was smiling because she was lying. According to the theories of emotional neuropsychology, the asymmetrical smile is a manifestation of the human being when he lies or when his enjoyment is not genuine. Since Da Vinci was a great observer of human physiognomy, researchers speculate that the artist knew the true meaning of the asymmetrical smile, which could represent a strategy that he deliberately used to hide cryptic and enigmatic messages.
Another well-known theory proposes that the smile was caused because the thyroid gland was underactive. Mandeep Mehra in 1959, professor at Harvard University and medical director of the Brigham Heart and Vascular Center, first explained that due to the inclination of the mouth, the swollen neck, and the hairline, the woman suffered from a disease related to hypothyroidism. In addition, he suggested that the yellow tone of her skin could be a symptom of increased dermal levels of total carotenoids. In fact, Mehra stated that the disease was common during the 14th century because the diet of the Italians was low in iodine.
But this is not the craziest theory. David Thaler, an expert in Genetics, Microbiology, and Biotechnology at the University of Basel, Switzerland, has studied Da Vinci’s writings and concluded that the artist possessed unusual visual abilities. It seems that he was able to detect movements that were imperceptible to most people and store them in his memory. Specifically, it corresponds to a concept known as “critical flicker fusion frequency” (CFFF). In his description of dragonflies, Da Vinci noted that “it flies with four wings and when the front wings are raised, the rear wings are lowered”. It is unusual that the Renaissance man could make this observation at that time since it was only possible with high-speed cameras that were later invented in the 20th century. Therefore, this superhuman quality would have allowed Da Vinci to paint an imperceptible smile that would cause an illusion that oscillates between smile and seriousness.
But the truth is that Da Vinci, after years of research, noticed that the smile was one of the most meaningful expressions and that is why he focused on it. This is how Vincent Delieuvin, a specialist in Renaissance art, explained it. In fact, this smile is not exclusive to the Mona Lisa, but is also present in “The Lady in Ermine” (1490), “La Belle Ferronière” (1490-1499) and “This Portrait of a Woman” (1474-1476). The smile is nothing more than a trick of the artist achieved with the sfumato technique. This method eliminates the clear lines and blurs the contours to merge those mysterious smiles with the rest of the face. This causes a vaporous effect, an aspect of vagueness and remoteness. In this way, the smile disappears when you look directly at it and only reappears when your eyes are fixed on other parts of the work.