It really seems to boil down to a big ol' "I dunno" from science, which is at least a bound on the virtues/dangers of the approach if nothing else.

As someone who is actually relatively interested in science, I have noticed that it isn't very helpful when it comes to parenting, except in a few cases which tend not to be very surprising ("hey, don't smoke around your baby"). The studies are so small and there are so many confounding factors I almost wonder why they try.

I'm satisfied with our outcome, nobody got exhausted and we're in a pretty good position now, but who really knows why?