Note to self: in red

The Informed Reader (B12) scoops the Nov. 12 Cognitive Daily. Apparently, red pens DO have an adverse effect on students. I know this well; fortunately, several of my instructors have used green pens, for a very calming paper appearance. The question is: is fear of red "instinctual" or does inspire fear from a Pavlovian conditioning? Or is it that "in nature, a lot of unpleasant things are red, starting with blood, hot coals and lava"?

A short test--which looks better?

94% -- Keep up the good work! OR


94% -- Keep up the good work!