The debate over whether parents should leave a wailing baby to “cry it out” or rush to their aid has been reignited by research that suggests allowing them to bawl does no harm.
Attachment theory suggests parents should dash to calm their infants, and proponents say leaving infants to cry could have knock-on effects including damaging the bond between parent and child and raising the infant’s stress levels.
Others, however, argue that picking a baby up reinforces crying, and that parents should leave the child.
Now researchers say they have found that leaving infants to cry has no impact on their behavioural development or their attachment to their mother, but may help them develop self-control.
Prof Dieter Wolke, the co-author of the study from the University of Warwick, said the findings suggest parents should not worry too much about which approach they take.
“We may have made a mountain out of a molehill,” he said.
Amy Brown, a professor of child public health at Swansea University who was not involved in the research, said the study should be treated with caution. Few mothers in the study often left their infant to “cry it out” until they reached 18 months, she said, and the study did not consider how long parents left their child or whether they found it helpful.
“This doesn’t prove that controlled crying is a beneficial thing,” she said. Nor does the study “talk about how distressing a lot of mothers find it when their baby cries”.
Writing in the Journal of Child Psychology and Psychiatry, researchers from the University of Warwick report how they followed 178 babies and their mothers in the UK from birth to 18 months.
Mothers were asked to fill in questionnaires to report how often they left their baby to “cry it out” at several points in time: shortly after birth and at three months, six months and 18 months. They were also asked how often and for how long their child cried at various point in the day as a newborn and at three months and 18 months.
At three and 18 months the team explored how sensitive the mother was towards their infant, using video-recorded interactions between the two, and at 18 months it assessed the children’s behavioural development and attachment to their mother.
The team found mothers rarely left their baby to cry as newborns, but the practice became more common as the child grew older, with about two-thirds of mothers allowing the infant to cry sometimes or often by 18 months.
That, the researchers add, appears to bring benefits, noting that children left to cry a few times as newborns cried for shorter periods at 18 months.
The team say the practice seems does not seem to cause harm. It saw no negative impact on the level of attachment between mother and child, the mothers’ sensitivity or the behavioural development of the child at 18 months, the latter assessed through a combination of techniques including a questionnaire completed by the parent, a psychologist’s report and watching the infant play with its mother.
“We neither recommend leaving infant to cry out nor responding immediately,” the authors write. Wolke said the findings suggested parents intuitively know how to best to respond to their infant, and both they and the child adapt over time.
He also said the research did not mean parents should just ignore a crying infant, particularly early in life.
Crying is “the only way of communication of a baby, for example for feeding, safety and things,” he said. So caregivers “should react to the crying, and automatically we do this.” Letting the baby cry for a few minutes may be helpful though, he added, particularly if it is not feeding time. “Then they can learn how to self-soothe themselves,” he said.
The study has limitations, including that it relied on reports of crying rather than direct observation. Nor was it able to unpick whether leaving the child to wail is the cause of shorter subsequent crying periods.
Wolke said that because of parents’ strong attitudes on the topic, it would not be possible to carry out a randomised control trial to explore the issue.
Dr Charlotte Faircloth, an expert on parenting from University College London, said the “cry it out” issue was hotly debated.
The new study “will be reassuring for many parents who have used these kinds of approaches with their babies, but as the study authors suggest, more credit should be given to parents in trusting that they will find an approach that suits them and their families,” she said.
Stephen Scott, a professor of child health and behaviour at King’s College, said a number of studies had shown that overindulged children can lack resilience and develop difficulties later in life.
He also said the latest findings made sense from an evolutionary point of view. “It is very unlikely that in the jungle when we were in our caves and off hunting, that a child left to cry for a bit would then be damaged by it,” he said. “It just wouldn’t make for a very resilient species, and yet we are incredibly resilient.”