By Greg Dardis / Guest Column

The cover story of The Atlantic’s November issue offers a fascinating explanation for Leonardo da Vinci’s creative genius: It straddled the arts and sciences.

His ability to fuse the two realms peaked with the “Mona Lisa,” which da Vinci worked on for most of the last 16 years of his life.

The article breaks down the use of anatomy, chemistry and art that resulted in an image that seems to smile back at you.

To begin, da Vinci prepared his canvas differently. Working off a thin plank of poplar tree, he ap­plied a primer of lead white rath­er than the standard mix of chalk and pigment. He knew it would be better at reflecting the light that penetrated many layers of translu­cent glazes. Viewers see light rays that bounce off the painting’s sur­face as well as those that shimmy forth from its depths. This creates the uncanny sensation that her smile shifts as the viewer moves.

Da Vinci used various techniques to enhance the sense of aliveness. His paint, for example, contained less pigment than usual mixed into its oil, which allowed him to apply thin, tiny strokes that bring about a 3-D effect. For the shadows that form Mona Lisa’s smile, da Vinci pioneered a brown glaze made of iron and manganese. The glaze ranges from just two micrometers at its thinnest to 30 micrometers in the deepest shad­ow, creating a remarkable depth.

Da Vinci’s methods illustrate his anatomi­cal knowledge, acquired during nights spent at a hospital morgue near his Florence studio. There, he peeled the skin off cadavers to study the muscles and nerves underneath. He was determined to understand how a smile begins to form.

Da Vinci also understood optics: an object appears sharp when looked at straight on and blurrier when glimpsed from the corner of the eye. This knowl­edge helped da Vinci create an interactive smile. Viewed direct­ly, “Mona Lisa” does not appear to be smiling. But as your gaze shifts, the shadows at her mouth’s edge make her lips turn upward into a soft smile.

The power of a smile is not lost on me. In our public-speaking program, we address a host of physical skills, from eye contact to a balanced stance to the position of your hands. Facial ex­pressions are key. We ask clients how they want to be perceived when they give a presentation. Enthusiastic? Approachable? Credible? For far too many professionals, their facial expressions contradict this objective.

A smile sets the tone, is reciprocated and re­flects something positive. Its message is vital for any public speaker: that she’s happy to be there. Imagine how an audience would feel if, absent a smile, a speaker appeared obligated – or, worse yet, tortured by the task at hand. This is often implied when a speaker is not mindful of his or her facial expressions.

The good news is, just as we can train our­selves to resist filler words or adjust our pacing as a speaker, we can also develop greater aware­ness of our facial expressions. They matter not only when we speak but when we listen. Here it’s especially easy to overlook the message on your face. During a public presentation, do you ap­pear grateful for someone’s question or irritated by it? In a board room, do you look interested in another’s comment or bored by it?

Many people furrow their brow when they are concentrating. Consider how your supervi­sor may feel if you seem to frown every time she speaks to you.

A smile can even be heard on the phone. We’ve encouraged clients to place a mirror in front of them to help manage how they sound in a conference call.

It all adds up to a consistent, lasting message: You look the part, you sound the part, you know the part. You speak as well as you think.

Greg Dardis is the CEO of Dardis Communications, based in Coralville. For more information, visit www.dardiscommunications.com.