For me, both tactics were employed. First the logic: “Don’t/do this because…”. Naturally as a young child, curiosity causes us to push boundaries, so that rarely worked first time. And so then came the fear: “Dont’t/do that again or (…) will happen”. And if that didn’t work, then the fear was followed through with reality. And I have to say, it was a very effective mix of logic and fear depending on which tactic was required.