Sleep Training Truths: What Science Can (And Can't) Tell Us About Crying It Out

Welcome to parenthood! For many of us, parenthood is like being air-dropped into a foreign land, where protohumans rule and communication is performed through cryptic screams and colorful fluids. And to top it off, in this new world, sleep is like gold: precious and rare. (Oh, so precious.)

Throughout human history, children were typically raised in large, extended families, filled with aunts, uncles, grannies, grandpas and siblings. Adding another baby to the mix didn't really make a big dent.

Nowadays, though, many moms and dads are going about it alone. As a result, taking care of a newborn can be relentless. There are too few arms for rocking, too few chests for sleeping and too few hours in the day to stream The Great British Bake Off. At some point, many parents need the baby to sleep — alone and quietly — for a few hours.

And so, out of self preservation, many of us turn to the common, albeit controversial, practice of sleep training, in hopes of coaxing the baby to sleep by herself. Some parents swear by it. They say it's the only way they and their babies got any sleep. Others parents say