The biggest reason why the solutions that work for one parent don’t work for another is simple. They’re not dealing with the same baby. Some babies are heavily reliant on sleep props. Others can’t sleep in a room that’s too warm. Some may not be getting enough daytime sleep, and others might be overtired. This baby might have developed an association between feeding and falling asleep, whereas that one might be ready to drop their second daytime nap. And, of course, it could be any combination of all of the above, or the many other sleep challenges that babies might experience.
The benefits of sleep training baby can be substantial: Everyone in the household will be well rested, and sleep is essential to baby’s development. A landmark 2007 study from the National Institutes of Health suggested that critical brain-development periods are dependent on adequate sleep. “Sleep training baby may not be fun, but I always tell families that it’s not dangerous, and developing good sleep hygiene is, in my opinion, one of the best things you can do for your child,” Gold says.
"The more practice your baby gets putting himself to sleep, the quicker the process works. He will fall asleep on his own, and you will get the sleep you need...Don't wait too long, though. The earlier, the better. Remember, once your baby gets older – that is, at least 5 or 6 months – the process of getting your child on a sleep schedule and to sleep through the night gets more difficult."
If your baby is older than six months, don’t worry, McGinn says: “It’s never too late to develop good sleep habits.” Dickinson says he finds nine months to be a bit of a sweet spot for parents in terms of getting babies to sleep through the night. “They are at a good age for understanding routines and don’t need to eat during the night,” he explains.