This is a big subject and the answers are both technical and general. At some point I may try to summarise the evidence and arguments, but at this stage I am not sure that I could do the job as well as I would like without putting in a lot of research time I don't have.
The two best books on this subject that I have come across are David Dreman Contrarian Investment Strategies - The New Generation, and the classic Charles Ellis Winning the Loser's Game. If you have any trouble finding them, get onto The Educated Investor Bookshop in Melbourne (link on my web site). Janene will get them for you.