Cribsheet: A Data-Driven Guide to Better, More Relaxed Parenting, from Birth to Preschool (The ParentData Book 2)

by Emily Oster

“Cry it out” works, helps parents and kids sleep better, and improves parental mood and happiness. Is it harmful for your child? There are a number of good randomized trials that speak to this. One representative study from Sweden, published in 2004, took ninety-five families and randomized them into a sleep-training regime involving a form of “cry it out.”8 The authors focused on whether behavior during the day was impacted by the nighttime—basically, they asked whether the infants were less attached to their parents during the day as a result of being left to cry during the night. This particular study found that, in fact, infant security and attachment seemed to increase after the “cry it out” intervention. It also found improvements in daytime behavior and eating as reported by the babies’ parents. Note that this is the opposite of the concerns raised about “cry it out” methods. This study is not alone. A 2006 review of sleep-training studies, which included thirteen different interventions, noted the following: “Adverse secondary effects as the result of participating in behaviorally based sleep programs were not identified in any of the studies. On the contrary, infants who participated in sleep interventions were found to be more secure, predictable, less irritable, and to cry and fuss less following treatment.”9 (Translation: Nothing bad happened in any study, and in most cases, the babies seemed happier after sleep training than before.) More recent studies draw t...