The fact that this is so commonplace in my culture (USA) is frustrating and enrages me. As a parent, it is your evolutionary instinct to comfort a crying infant. They are quite literally helpless and look to caretakers for all their needs. There's a deep seated biological reason it feels bad to ignore it. The fact that it is so uncommon in other cultures should make this obvious. What are the odds that the rest of th…
The article makes fairly clear that sleep training under 6 months is not advised. Not to say that every baby will be ready at that point, but it becomes clear to most parents somewhere in the first year what cries from their baby express sincere needs - even psychological- and which are just gratuitous attention seeking. Once they have object permanence down, parenting changes.
Beyond that - the close presence of parents near the infant until 2 years of age was discovered to be vital for the infant's development, social skills and especially being bold enough to experiment and learn new things. The lack of parents in close proximity in that period causes the infant to feel anxiety and hesitate from wandering around and trying out things and learning.