Experiment interface.

<p>This screenshot was taken during a pilot <i>increment</i> session, after all decisions had been submitted, and as all decisions and rewards in a round were being reported. Participants saw their own choices as the red ‘X’. Previous experiments have tested the same rule with visual arrangements besides the circle <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0056416#pone.0056416-Frey1" target="_blank">[39]</a>. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0056416#pone.0056416.s002" target="_blank">Video S1</a> for the complete video for a typical session.