My work was on preschool-aged parent-child relationships and nursing intervention.
It concludes that the interventions in the training of the parents in the exercise of parenting (and discipline in the parenting) lead to an improvement in the behavior and the parents-child relations after the intervention, improvements that maintains over time.
This improvement in parent-child relationships can positively influence their future development on an emotional, relational, intellectual, social level.
Therefore, there must be changes in the parents' intervention with their children.
I do not recall studies on the subject that I can recommend. But I suggest doing a systematic review of literature on the subject to see what you can find.
I have attached the article I have available on my work.