Ignoring the child builds character
It used to be common knowledge, especially by the “behaviorist” trend, that parents shouldn’t be too attentive towards the kid. Don’t congratulate them for their achievements, basically, ignore them. It was supposed to build character.
Babies in a cage
Around 1940, the latest parenting trend was that if you lived in a high floor and had no balcony or garden, you could just put your baby in a metal cage and hang it from the window so he can get some air.