I think "let kids think for themselves" and "encourage good/discourage bad behavior" are correlated in a way that is opposite what you implied: being able to come to your own conclusions means that whatever behaviors you end up practicing (in a healthy environment, good ones, encouraged by parents/others) are your own choices, rather than things you'll slavishly repeat for fear of punishment/desire for praise later on in your life.

Tl;dr parents can encourage/punish their kids and let them think for themselves. This is healthy and good.

Also, to loop back to the larger discussion, using screens definitely doesn't discourage bullying behavior. For evidence I present . . . the internet, give or take.

And the time to start worrying is when you hear the loud thump... and then there's just silence.

(Speaking from experience -- it was scary, but he recovered.)