The Atlantic's science writer, Sam Keen, recently looked at a study that compared posing in portraits. He found that in a disproportionate number of images the subject was turned slightly to the right. Coincidence? He thinks not.
As stated in the video, if you were to walk into a portrait gallery you might expect to see about 1/3 of the subjects looking forward, 1/3 of them looking to the right and the remaining 1/3 looking to the left, but this doesn't seem to be the case. In the study referenced, over 60% of the subjects were turned to the right, showing the left side of their face. Sam believes this favoritism for the left side of peoples faces, or a subject's natural tendency to highlight that side is related to the part of the brain responsible for its use. He explains that the left half of the body is controlled by the right half of the brain which is also responsible for emotion and communication, making it more pleasing to look at and more likely to convey emotion.
Take a look:
[Via The Atlantic]