Maybe im taking this too seriously but I dont think that your theory holds much water.

Some tests need to be negative and some positive. The fact that an author has used one or the other is indicative of the needs of the code and not the psychology of the author. For insantce the two regexes you show are not interchangable, so psychology cannot have been responsible for choosing one or the other.

--- demerphq
my friends call me, usually because I'm late....