Does this gif hurt your brain? You're not alone.

Ever wonder why side-scrolling video games from the 80's and 90's almost always scroll in a single direction—left to right? This might seem like a silly question (duh...it just makes sense that way), but if you really think about it, it is a little odd. Why do games always scroll that way?


Turns out, our knee-jerk reaction that left to right just "makes more sense" has now been legitimized by science. Our brains vastly prefer left to right motion, according to Lancaster University psychologist Peter Walker. That conclusion, based on Walker's analysis of thousands of images of people and objects in motion, is published in the journal Perception.

"What artistic conventions are used to convey the motion of animate and inanimate items in still images, such as drawings and photographs?" Walker said in a press release. "One graphic convention involves depicting items leaning forward into their movement, with greater leaning conveying greater speed. Another convention, revealed in the present study, involves depicting items moving from left to right."


Interestingly, the bias only seems to apply to images of moving objects. When a person or object is stationary in a photograph, there's equal likelihood of a left or right-facing pose, Walker finds.

"This could indicate a fundamental left-to-right bias for visual motion," he said.

The left to right bias can also be found in typography: Italics, used to convey motion or speed, always appear to be moving from left to right, even in Hebrew texts where the reader's eyes scan right to left.


Sure, we might have already known that Super Mario is better than Super Luigi, but it's always nice to have science on your side.

Read the full scientific paper at Perception.

Top image via YouTube