Behavioural science (if it can even be called a "science") is a mess of lousy experiments, apocryphal conclusions, and failed generalizations.
There *are* some precious exceptions, but in general you're no more and no less likely to obtain good, peer-reviewed "objective" parenting advice than you are asking random strangers on the Internet.
Apologies to any behavioural scientists in the crowd, but your legacy speaks for you.