Mona Lisa Effect is a myth as her eyes do not follow you across the room, say scientists

Sarah Knapton
Prof Gernot Horstmann and Dr Sebastian Loth pictured between the Mona Lisa  - CITEC/ Bielefeld University

The Mona Lisa effect, where the eyes of a painting seem to follow you across the room, does not actually work for Leonardo’s portrait, scientists have concluded.

The phenomenon occurs when a subject is painted, or photographed, looking directly at the artist, but once the angle of the eyes moves past five degrees from the centre of the camera or painter the eyes no longer appear to follow a viewer around the room. 

However, German psychologists have measured the angle of the Mona Lisa’s eyes in the 16th century oil painting and found her gaze sweeps to around 15 degrees, so at best, she is glancing at the viewer’s right ear.

A picture released by the team in which they stand between the painting looking directly into the camera clearly shows her eyes are off kilter. 

So if people feel they are being watched by the painting it is purely psychological, which could indicate a desire to be the centre of attention, the study concludes.

“The Mona Lisa effect itself is undeniable and demonstrable,” said  Dr Sebastian Loth of the Cognitive Systems research group, at Bielefeld University.

“We don’t have to stand right in front of the image in order to have the impression of being looked at – even if the person portrayed in the image looks straight ahead.

“This impression emerges if we stand to the left or right and at different distances from the image. The robust sensation of ‘being looked at’ is precisely the Mona Lisa effect. But with the Mona Lisa, of all paintings, we didn’t get this impression.”

The eyes of the Mona Lisa look slightly to the right, dispelling the illusion  Credit:  CITEC/ Bielefeld University 

The Mona Lisa, which is thought to be a portrait of Lisa del Giocondo an Italian noblewoman, and painted between 1503 and 1506. For hundreds of years experts have puzzled over her enigmatic smile and unshakeable eyes.

It is now thought that Mona Lisa effect occurs because although shadows and light on a three dimensional face shift as our vantage moves, in a two dimensional painting they stay the same, so we have the perception that they eyes have not moved and continue to stare at the viewer.

To find out if the it worked for the Mona Lisa the team asked 24 participants to look at the painting on a computer screen and assess the angle of her gaze using a ruler positioned at several distances to their side.

After running the test 2,000 times, every single measurement indicated that the portrait’s gaze was not straight on but to the viewer’s right-hand side at an average of 15.4 degrees.

“The participants in our study had the impression that Mona Lisa’s gaze was aimed to their right-hand side,” said Professor Gernot Horstmann of Bielefeld University’s Department of Psychology.

“Thus, it is clear that the term “Mona Lisa Effect” is nothing but a misnomer.

“It illustrates the strong desire to be looked at and to be someone else’s centre of attention – to be relevant to someone, even if you don’t know the person at all.”

Since the 1960s scientists have known that humans have an instinctive ability for knowing when they are being watched, and often feel they are being looked at by paintings and photographs.

“With a slightly sideward glance, you may still feel as if you were being looked at,” added Prof Horstmann. “This was perceived as if the portrayed person were looking at your ear, and corresponds to about five degrees from a normal viewing distance.

“But as the angle increases, you would not have the impression of being looked at.”

The research was published in the journal i-Perception.