Letting a baby “cry it out” from birth up to 18 months doesn’t adversely affect their behavior development or attachment, researchers report.
They also discovered that those left to cry cried less and for a shorter duration at 18 months of age.
In their new paper, researchers focus on an issue that parent websites and parents have discussed for decades without much scientific evidence: Should you always immediately intervene when your baby cries?
Researchers followed 178 infants and their moms over 18 months and repeatedly assessed whether parents intervened immediately when baby cried or let the baby let it cry out a few times or often. They found that it made little difference to the baby’s development by 18 months.
In fact, they found leaving babies to cry it out a few times at term and often at three months was associated with shorter crying duration at 18 months.
Researchers assessed the use of parents leaving their baby to “cry it out” via maternal report at term, three, six, and 18 months and cry duration at term, three, and 18 months. Researchers assessed duration and frequency of fussing and crying at the same ages with the Crying Pattern Questionnaire.
Video recordings showed how sensitive mothers were in interacting with their baby and researchers rated the videos at three and 18 months of age.
They assessed attachment at 18 months using a gold standard experimental procedure, the strange situation test, which assesses how securely an infant is attached to the major caregiver during separation and reunion episodes.
The researchers assessed behavioral development via direct observation in play with the mother and during assessment by a psychologist and a parent-report questionnaire at 18 months.
Researchers found that whether contemporary parents respond immediately or leave their infant to cry it out a few times often makes no difference on the short- or longer-term relationship with the mother or the infant’s behavior.
This study shows that two-thirds of moms parent intuitively and learn from their infant, meaning they intervene immediately when they were just born, but as the baby gets older, the mother waits a bit to see whether the baby can calm themselves, so babies learn self-regulation. This “differential responding” allows a baby to learn over time to self-regulate during the day and also during the night.
“Only two previous studies nearly 50 or 20 years ago had investigated whether letting babies ‘cry it out’ affects babies’ development. Our study documents contemporary parenting in the UK and the different approaches to crying used,” says Ayten Bilgin of the psychology department at the University of Warwick.
“We have to give more credit to parents and babies,” says Dieter Wolke, the professor who led the study.
“Most parents intuitively adapt over time and are attuned to their baby’s needs, wait a bit before intervening when crying, and allow their babies the opportunity to learn to self-regulate,” Wolke says. “Most babies develop well despite their parents intervening immediately or not to crying.”