Source: http://m.nautil.us/blog/why-tinder-charm...

In the visual design of the app, Tinder’s founders capitalized on a bit of human psychology: It seems natural that a positive feeling should be indicated with a rightward swipe rather than a leftward one. In theater directing1, rightward motion is believed to be perceived by the audience as good, and leftward bad, and studies have backed it up. In the film “The Matrix,” most of the time Keanu Reeves’ character gets into a fight, he’s moving left to right on the screen, and his enemy is doing the opposite. Almost every video game ever made that scrolls to one direction has the player’s avatar moving left to right. (Jungle Hunt is the only side-scroller game I know of that has exclusively right-to-left scrolling; in some others, you go both directions.) Studies even show that referees call more fouls on players moving left in their visual fields.