The Even Effect: The Human Brain Processes Even Digits more Rapidly than Odd.

Four experiments tested a hypothesis that even digits should be cancelled out more rapidly than odd in digit cancelling performance using as subjects of 436 elementary school children, and 449 undergraduates. The dominance of even over odd was observed using materials from both Arabic and Chinese character numeral systems. The effect was also supported in a reaction time experiment. These findings suggest that the processing time of even digits may be different from that of odd in numeral mental operation.