The Mona Lisa effect describes the phenomenon where the eyes in a portrait seem to follow the person looking at it, no matter where the person stands in the room. The effect was obviously named after Leonardo da Vinci's famous painting featuring the woman with the enigmatic smile and the iconic gaze.
But ironically, a new study finds that Mona Lisa may not be all that interested in tracking her observers.
Two researchers from Bielefeld University in Germany found that the famed subject of the painting, also known as "La Gioconda," is actually looking just over your right shoulder.
"People are very good at gauging whether or not they are being looked at by others," says psychologist and study co-author Gernot Horstmann, who specializes in eye movement and attention, in a statement.
Measuring Mona Lisa's gaze
For the experiment, Horstmann and his research assistant Sebastian Loth gathered two dozen participants to take a look at the eyes of the painting. But they didn't just ask them if they thought Mona Lisa was looking their way. Instead they displayed part of her face on a computer screen, then asked volunteers to measure her gaze using a carpenter's ruler that was held horizontally between them and the screen.
Although the computer screen and the participants stayed in the same spot, the ruler was moved closer and farther from the screen during the trial. In addition, the researchers changed the size of Mona Lisa's face and how much of her features were visible to see if that changed the perception of her gaze. The images showed varying degrees of zoom — from 30 to 70 percent — with some showing her entire face and others showing just her eyes and nose. The researchers also moved the images several centimeters to the left and to the right, so the participants wouldn't just pick the same measurement on the ruler each time.
Horstmann and Loth published their results in the journal i-Perception where they were very clear in their conclusion.
"We conclude from the measurements that the lack of evidence is due to the claim being objectively false: Mona Lisa does not gaze at the viewer," they wrote. "There is no doubt about the existence of the Mona Lisa effect — it just does not occur with Mona Lisa herself."