Research published in Journal of Child Psychology and Psychiatry They found that letting babies cry every now and then does not impair their behavioral development or their bond with their mothers. This study suggests that parents who let their infants fuss for a while are not causing long-term psychological damage. These results provide reassurance to parents navigating the daunting challenges of infant sleep and crying.
For decades, parents and psychologists have debated how quickly caregivers should respond to a crying baby. One school of thought, based on attachment theory, suggests that parents should immediately soothe a crying baby. Attachment theorists argue that quick responses help infants form a secure emotional bond with their caregivers.
A secure bond gives the child the confidence to explore the world, knowing that the parent is a safe place. Another perspective comes from behaviorism, a branch of psychology that focuses on how learning shapes behavior. Behaviorists suggest that immediately comforting a crying baby may inadvertently reward the crying baby, leading to more tears in the future.
They suggest that giving your baby a chance to cry out loud can reduce crying overall. Parents may step back and give their children space to learn how to soothe themselves. Psychologists Eiten Bilgin and Dieter Wolke set out to test these contradictory ideas.
Bilgin is a researcher at the University of Warwick, UK, where Wolk is a professor. They wanted to see how different approaches to crying affect infant development over time in a modern context.
“In previous research, either 50 or nearly 20 years ago, only two studies looked at whether letting babies ‘cry’ has an impact on their development. Our study documents contemporary parenting in the UK and the different approaches to crying,” Bilgin said.
The first of the older studies was conducted in 1972 and included only 26 families. This early research suggests that ignoring crying can lead to more crying, creating an insecure attachment. Subsequent attempts to replicate these results have shown contradictory results, leaving modern parents with no clear guidance.
To collect more reliable data, Bilgin and Wolke followed 178 infants and their mothers from birth until 18 months of age. The researchers followed a combination of babies born at term and those born prematurely or with low birth weight. Mothers reported how often they made their babies cry at birth, at 3 months, 6 months, and 18 months.
Mothers indicated whether they used this approach never, once, a few times, or often. We also recorded the time and frequency of the baby’s crying in the morning, afternoon, evening, and night. When the babies reached 18 months of age, researchers used multiple tools to assess their behavioral development.
Independent observers observed the infants’ play and assessed their attention span, hyperactivity, and social skills. They assessed toddlers on their ability to stay on task and overall emotional tone. Parents also completed a questionnaire detailing any behavioral problems they noticed at home.
The researchers also measured the emotional bond between mother and child using an established psychological test called the Strange Situation Procedure. In this laboratory test, researchers observed how infants react when their parents leave the room and return. This brief separation ensures that the infant’s attachment behavior is triggered.
This test helps classify your child’s attachment style. Being securely attached means that your child feels safe to explore and that you can easily reassure them when they return. Insecure attachment means that the child may avoid the parent or show high levels of anxiety and resistance.
Researchers have found that it is rare for babies to stop crying immediately after birth. Most mothers responded immediately to their newborns. As the baby grows, parents often let the baby cry several times or frequently.
Allowing babies to cry occasionally soon after birth was associated with less crying at 3 months of age. Letting infants cry several times at birth, and often during the first three months of life, was associated with shorter crying times when the child reached 18 months. Results regarding adverse effects on infant development were not statistically significant.
In fact, this study found no negative effects on infant-mother attachment at 18 months of age. Babies who were put to cry developed a strong bond, just like babies who were immediately comforted. The researchers also found no negative effects on young children’s behavioral development, such as increased aggression or hyperactivity.
Professor Wolke pointed out that parents naturally adjust their parenting as their children grow. “We need to evaluate parents and babies more. Most parents adapt intuitively over time, attuning to their baby’s needs and waiting a moment before intervening when they cry, giving their baby a chance to learn self-regulation. Most babies develop well even if the parent intervenes right away or doesn’t cry.”
This study has several limitations that readers should be aware of. The researchers measured how often babies cried and how often parents made babies cry, based on mothers’ self-reports. Although maternal reports are generally reliable, independent observation over the entire 18 months would have provided more objective data.
The study was also observational and could not prove a direct causal relationship between parenting choices and infant behavior. This study did not measure crying frequency at 6 months, leaving a small gap in the timeline. Finally, the questionnaire did not ask parents to differentiate between daytime crying and nighttime crying.
Following the announcement, researchers Avi MB Davis and Robin SS Kramer published a commentary questioning the study’s conclusions. They argued that ignoring infant cries goes against human evolutionary impulses. Children cannot verbally communicate their pain or hunger, so crying is their main means of survival.
Davis and Kramer suggested that failure to respond may increase stress levels in infants. They pointed to previous theories suggesting that elevated stress hormones such as cortisol can negatively impact brain development. They expressed concern that parents would read this study and start ignoring the real needs of their infants.
The authors of the commentary also expressed concerns about the statistical power of the study. They argued that the sample size of 178 infants was too small to confidently detect a minor negative effect on attachment type. They were concerned that grouping different types of insecure attachment would mask subtle issues.
Additionally, Davis and Kramer noted that the study did not provide parents with a strict definition of what it means to let their baby cry. Without clear definitions, mothers may have interpreted the questions differently. Some people may have imagined leaving their child alone in their crib, while others may have imagined sitting in the same room as the child while they fuss.
Bilgin and Urke later published a detailed response to this criticism. They clarified that their study does not recommend ignoring crying babies completely. Their findings simply showed that modern parents are not harming their children if they sometimes delay responding.
The original authors pointed out that an experiment in which parents were randomly assigned to ignore their babies would be impossible and unethical. Parents have strong personal views on parenting and do not agree with being randomly assigned a parenting style. For this reason, observational studies remain the best option for understanding these dynamics.
Addressing statistical concerns, Bilgin and Wolke explained that the sample size was large enough to detect meaningful differences in attachment. They highlighted that none of the three recent studies, which followed 365 infants, found an association between delayed responding and insecure attachment. The only study that found a negative association was a 1972 project that involved just 26 families.
Bilgin and Ulke also challenged the idea that crying causes dangerous stress. They cited an independent study that found sleep training programs did not increase stress hormone levels in infants. In fact, when mothers stopped rushing and intervening, their stress hormones decreased.
The researchers emphasized that a mother’s sensitivity during play and daily interactions is what truly creates secure attachment. They found no differences in maternal sensitivity observed between mothers who let their babies cry and mothers who did not. Being slow to react at bedtime doesn’t mean you’re an insensitive parent.
In the future, the researchers hope to investigate how different types of crying require different responses. Future research could separate daytime fuss from nighttime awakenings to see whether the effects of delayed response vary by time of day. Clearer insights may also be gained by tracking specific parental behaviors, such as whether the parent was in the room while the baby was crying.
A larger sample size helps scientists detect even smaller changes in infants’ behavioral patterns. By combining data from multiple studies, psychologists can build a more comprehensive picture of how babies learn to manage their emotions. Ultimately, observing how parents naturally adapt to their infants over time can provide ongoing understanding of child development.
The study, “Parental Use of ‘Cry’ in Infants: No Negative Effects on Attachment and Behavioral Development at 18 Months of Age,” was authored by Ayten Bilgin and Dieter Wolke.
