I think the case you mentioned is explained by an idea covered in attachment theory. Children explore when they feel safe and secure. Safety and security come from the caregivers, the parents. When that is absent, because the parents' emotional state makes the children feel insecure, then the children are restrained by their own emotions.
How?
People do studies on weeks old babies, it seems unlikely curiosity has been restrained at that point.
Good point!
I think the case you mentioned is explained by an idea covered in attachment theory. Children explore when they feel safe and secure. Safety and security come from the caregivers, the parents. When that is absent, because the parents' emotional state makes the children feel insecure, then the children are restrained by their own emotions.