There is a popular belief among some parents that you should never let their child cry at night in order to help him or her sleep better. They believe that this action damages the bond between the mother and infant.
Is this belief based on a scientific foundation, or not? In other words, are there academic journal articles based on empirical evidence that support this belief?
One study of 26 infant-mother pairs, in the 1960s found that leaving an infant to cry it out was associated with insecure infant-mother attachment. The investigators who recorded whether crying it out did or did not occur were the same investigators who measured attachment. Thus, because there was no blinding, bias cannot be excluded.
Three exact replication studies have been conducted on a total of 365 mother-infant pairs and all showed no evidence of an association between leaving an infant to cry it out and attachment. Two of these studies (on 315 mother-infant pairs) were blinded; the researchers who recorded attachment did not know which parents had or had not let their child cry it out.
Many other studies (Blog Post 24) using other methods of measuring attachment between mother and infant also show that letting your child cry at night in order to help him or her sleep better does not disrupt mother-infant attachment.
What Do Your Believe and Why?