Just recently over on the main community wikia, a blog was created that discussed behavioral patterns regarding new users that have made bad edits, as well as vandals. The blog covers possible thought processes behind these random edits, and how best to react to them.
Personally I find a lot of it to be very truthful, and have witnessed a good deal of it firsthand myself. It makes for a solid and informative read, I will supply the link right here: Converting Conflict to Calm, by Sannse.