An infant’s development and attachment to their parents is not affected by being left to ‘cry it out’ and can actually decrease the amount of crying and duration, researchers from the University of Warwick have found. In the paper they deal with an issue that is discussed for decades by parent websites and parents without much scientific evidence:
Researchers followed 178 infants and their mums 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 3 months was associated with shorter crying duration at 18 months.
The use of parent’s leaving their baby to ‘cry it out’ was assessed via maternal report at term, 3, 6 and 18 months and cry duration at term, 3 and 18 months. Duration and frequency of fussing and crying was assessed at the same ages with the Crying Pattern Questionnaire.
How sensitive the mother is in interaction with their baby was video-recorded and rated at 3 and 18 months of age. Attachment was assessed 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.
Behavioural development was assessed by 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 to often makes no difference on the short – or longer-term relationship with the mother or the infants behaviour.
This study shows that 2/3 of mum’s parent intuitively and learn from their infant, meaning they intervene when they were just born immediately, but as they get 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.
Dr Ayten Bilgin from the department of psychology at the University of Warwick comments: “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.”
Professor Dieter Wolke, who led the study, comments: “We have to give more credit to parents and babies. 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. Most babies develop well despite their parents intervening immediately or not to crying.”
Background: Leaving infant to cry it out has been the subject of discussion among researchers and parents. Nevertheless, there is paucity of empirical research investigating the association between leaving infant to cry it out and consequent crying duration and frequency, mother–infant attachment and behavioural development.
Methods: The sample with complete longitudinal data comprised 178 infants and their caretakers. Parental use of ‘leaving infant to cry out’ and cry duration were assessed with maternal report at term, 3, 6 and 18 months, and frequency of crying was assessed at term, 3 and 18 months of age. Attachment was measured at 18 months using the strange situation procedure. Behavioural development of the infant was assessed with two observational measures and a parent‐report questionnaire at 18 months.
Results: The use of ‘leaving infant to crying’ was rare at term and increased over the next 18 months. ‘Leaving infants to cry it out’ at term was associated with a decrease in crying frequency at 3 months. Furthermore, leaving infants to cry it out a few times at term and often at 3 months was associated with shorter fuss/cry duration at 18 months of age. No adverse impacts of leaving infants to cry it out in the first 6 months on infant–mother attachment and behavioural development at 18 months were found.
Conclusions: Contemporary practice of some parents in the United Kingdom to occasionally or often ‘leaving infant to cry it out’ during the first 6 months was not associated with adverse behavioural development and attachment at 18 months. Increased use of ‘leaving to cry it out’ with age may indicate differential responding by parents related to infant self‐regulation.
Ayten Bilgin, Dieter Wolke