RED pen is bad for children's development. Or so say US researchers from University of Colorado who claim the pen colour can have a negative impact on how students feel about themselves and their teachers.

The Colorado study, published in the Social Science Journal, by sociology professor Richard Dukes and associate professor Heather Albanesi, claimed that red was an emotive colour that caused students to feel "shouted at".

Dukes and Albanesi said this "emotional loading" could alter the student's perception of criticism and place unnecessary blame on the teacher for bad marks or feedback.  They went on to suggest that teachers use blue pens if they wanted their comments to be taken in a constructive manner.

But can the colour of a teacher's pen really have such a negative impact on learning? The NSW Teachers Federation were contacted in regard to this story but refused to comment.

Amy Kirkham, director of training for the Montessori School Foundation of Australia, saw no problem with the use of red pen (or any other colour for that matter) so long as the teacher responds to the mistake in the right way.