The 'science' of boarding efficiency is questionable at best. It isn't about science, it is about perceptions....We might be smart animals, but we're still animals.

Airlines Go Back to Boarding School to Reduce Chaos ...
http://online.wsj.com/news/articles/...57930970524522

Best boarding strategy for airlines: random, study says
http://www.smartplanet.com/blog/smar...om-study-says/

The airlines' endless quest for better boarding
http://host.madison.com/business/the...57930970524522