Take a look at these paintings.
The "Mona Lisa" by Leonardo da Vinci.
Vermeer's "Girl With a Pearl Earring."
"Christ Crucified" by Diego Velazquez.
What do these paintings -- and a significant number of other historical pieces of art, especially portraits -- have in common? How about the turn that seems to highlight the left side of the face over the right.
According to NPR, there is a bias to the left side of the face, which has a connection to how the brain functions:
[…] when you look at someone, your right brain is doing most of the work. That's the side of your brain that specializes in faces and is extra good at reading emotions.
But — as you probably know — your right brain operates mainly through the left side of your body. So when you look at someone's face, your right brain pulls in information from the left of your visual field. Which means you will notice more, read more and remember more about the left side of that person's face. His right side matters less.
Sam Kean, who recently published the book "The Tale of Dueling Neurosurgeons," noted that "looking left" is distinctly seen in artistic works. Scholarly reviews of thousands of art pieces have confirmed this bias:
One study of 1,474 portraits painted in Europe from the 16th to the 20th centuries found that roughly 60 percent showed the sitter favoring the left side of the face — men 56 percent of the time, women 68 percent. Another study looked at 50,000 objects from the stone age to the present and found that after the early Greeks, there was a consistent left-profile bias. When it comes to Jesus suffering on the cross, the tilt is dramatic: Jesus' head is shown facing left more than 90 percent of the time.
The bias seems to have infiltrated other industries as well.
With most people naturally reading left to right, newspapers generally structure their design with the most important stories in the top left. Even the placement of news anchors could play off of this idea.
Only a few decades ago when the profession of reporting the news was traditionally male-dominated -- something recently satirized in the popular "Anchorman" movies -- the man sat on the right side of the desk to appear on the left to viewers.
Will Ferrell, playing Ron Burgundy in the "Anchorman" sits in what could be perceived as a more dominate position, compared to Veronica Corningstone, played by Christina Applegate. (Image source: YouTube)
Back to the art though, Kean pointed out that self-portraits seem to face right, which he thinks might actually "confirm the bias," because the artists were likely painting themselves in the mirror.
But then there are portraits of important scientists, which Kean found also often face right. This could be because "they simply preferred to seem cooler and less emotional — more the stereotypical rationalist," he told NPR.
Kean also argues that this bias in art is not necessarily a behavior taught in art school, finding that children, especially those who are right-handed, will draw figures with a bias to the left as well.