There are lots of myths and legends about the Mona Lisa—that it’s actually a self-portrait of DaVinci, that it includes hidden references to ancient literary works, that there are hidden codes made of numbers and letters hidden in her eyes. One of the most persistent ideas, though, is the Mona Lisa effect—the notion that no matter where art-lovers move around the room, the eyes of Lady Giocondo look directly at them.

German researchers recently put the Mona Lisa effect to the test, asking participants to take a close look at the painting. What they found is that the legendary effect isn't real, at least when it comes to the Mona Lisa.

Emily Dixon at CNN reports that cognitive scientists from Bielefeld University recruited 24 participants to give the DaVinci masterpiece a cold-hard look. They put an image of the painting up on a computer screen 26 inches away from viewers, then asked participants to use a long carpenter’s ruler to indicate where the painting’s eyes were directed. The measurements were repeated as the image was cropped and zoomed in 15 different ways, including images just showing the Mona Lisa’s eyes. The image was also slightly moved left and right to keep participants on their toes. In total, the team collected 2,000 measurements of the painting's perceived gaze.

The result? Most of the Mona watchers determined the painting was looking to the right at an average angle of 15.4 degrees, akin to having someone trying to look over your shoulder. “There is no doubt about the existence of the Mona Lisa effect—it just does not occur with Mona Lisa herself,” the researchers write in the journal i-Perception.

Even if DaVinci’s masterpiece doesn’t exhibit its namesake effect, other artworks do. “People can feel like they’re being looked at from both photographs and paintings—if the person portrayed looks straight ahead out of the image, that is, at a gaze angle of 0 degrees,” co-author Gernot Horstmann says in a press release. “With a slightly sideward glance, you may still feel as if you were being looked at. This was perceived as if the portrayed person were looking at your ear, and corresponds to about 5 degrees from a normal viewing distance. But as the angle increases, you would not have the impression of being looked at.”

Many other paintings do exhibit the Mona Lisa effect, including the impish gaze of Frans Hals' The Laughing Cavalier, which has helped researchers understand the phenomenon. But why do so many people attribute the same power to DaVinci’s masterpiece, which currently hangs in the Louvre? Horstmann theorizes in the press release that thinking the world’s most famous painting is looking at you is just a part of part of human nature. “It illustrates the strong desire to be looked at and to be someone else’s center of attention,” he says in the release, “to be relevant to someone, even if you don’t know the person at all.”

So if the Mona Lisa is glancing over your shoulder, it raises an even bigger question—who is standing right behind you, and why is she so happy to see them?