A psychologist believes side-scroller characters like Mario move from left to right because people have a bias towards depicting movement in that direction. Why exactly that should be is not so clear.
Dr Peter Walker of Lancaster University in the United Kingdom explored the topic in an article for the journal Perception titled: “Depicting visual motion in still images: Forward leaning and a left to right bias for lateral movement.”
As part of the study, he looked at thousands of picture on Google Images, looking in particular for still, art images (rather than photographs of the real world) that depict a scene of movement. He concluded that humans have “a fundamental left-to-right bias for visual motion”, based on his findings that:
- images of movement are disproportionately likely to have the moving character leaning forward;
- there’s a pattern that the faster the movement being depicted, the further forward the character is shown to be leaning;
- such characters are disproportionately likely to be shown leaning forward to the right rather than the left; and
- there’s no significant left/right bias in images where the character is depicted as stationary.
While it’s possible this might just be a feedback loop with artists and game designers influenced by existing works, Walker makes an argument that the fundamental bias continues in typography. He noted that designers often italicize words not purely for emphasis, but in situations where they want to “convey notions of motion and speed.” He added that such use of italics, with the ‘fast’ word leaning to the right, exists even in Hebrew typography where the reader moves from right to left.
It’s fair to note that Walker doesn’t offer any firm explanations of why the brain may associate leaning to the right (literally rather than politically!) with movement, so it’s still possible that our expectations are driven by our past experience of artistic images, rather than the other way around.
In a tangential way, it’s an issue I have some experience with as a pro wrestling follower. In most countries that have wrestling, performers are taught to stand in a particular position related to their opponent, put on holds with a particular arm, and to grab a particular leg or arm when putting on a hold. In turn this affects the direction in which they travel when being “thrown” into the ropes and “bouncing” back.
Wrestlers in Mexico are traditionally taught these conventions in the opposite ‘side’ from wrestlers in the rest of the world, meaning the relative positioning and the most common direction of movement in familiar sequences is the other way around. The result is that many viewers from other countries instinctively feel something is wrong when viewing Mexican matches on TV. While it might seem the answer is that it’s because they are watching six masked turtles rather than two men, the main explanation is that to a fresh viewer, so many conventions are reversed that it can feel like watching a TV image that’s been flipped 180 degrees.