I got minor curiosity about other countries' parenting over night

Hello! I'm Park from South Korea. Recently I heard western, especially the American, parents put their babies(even infants, toddlers) to sleep alone in their own room. It looks like very big cultural difference cuz none of Korean parents do like that.So it was very interesting and I wondered if it is just a traditional and cultural thing that having them sleep alone. Or if it is scientifically good for babies. And when babies go to bed, do parents keep baby's room absolutely dark or keep dim light? And can you hear when they cry while you are sleeping?Please tell me how you do over night. Thank you! via /r/Parenting https://ift.tt/32mImvk