All the ideology based practices in software engineering. TDD, xtreme programming, pair programming, BDD etc. This comment is going to rile up many, but I have

All the ideology based practices in software engineering. TDD, xtreme programming, pair programming, BDD etc. This comment is going to rile up many, but I haven't found anyone to show me even a half-ass scientific study to show that any of these things make anything better.