"Parents frequently pet and indulge their young children because it appears easier to manage them in that way. It is smoother work to let them have their own way than to check the unruly inclinations that rise so strongly in their breasts. Yet this course is cowardly. It is a wicked thing thus to shirk responsibility; for the time will come when these children, whose unchecked inclinations have strengthened into absolute vices, will bring reproach and disgrace upon themselves and their families. They go out into busy life unprepared for its temptations, not strong enough to endure perplexities and troubles; passionate, overbearing, undisciplined, they seek to bend others to their will, and, failing in this, consider themselves ill-used by the world and turn against it. 4T 201.2"
"The rod and reproof give wisdom: but a child left to himself bringeth his mother to shame."
The EGW passage directly expands on the principle of Proverbs 29:15, detailing the negative consequences of failing to discipline children.
"The lessons of childhood, good or bad, are not learned in vain. Character is developed in youth for good or evil. At home there may be praise and false flattery; in the world each stands on his own merits. The pampered ones, to whom all home authority has yielded, are there daily subjected to mortification by being obliged to yield to others. Many are even then taught their true place by these practical lessons of life. Through rebuffs, disappointments, and plain language from their superiors they often find their true level and are humbled to understand and accept their proper place. But this is a severe and unnecessary ordeal for them to pass through, and could have been prevented by proper training in their youth. 4T 201.3"
"Train up a child in the way he should go: and when he is old, he will not depart from it."
EGW's passage is a clear expansion on the principle of Proverbs 22:6, elaborating on the importance of early training and the consequences of neglecting it.