Cry It Out vs. gentle sleep methods: what the research really says

As a certified holistic sleep coach, I believe that baby sleep is more than just a routine – it’s a vital part of a child’s emotional and physiological development. While some sleep trainers promote methods like Cry It Out (CIO) for quick results, I take a different approach. My philosophy is rooted in gentle sleep methods that respect the baby's developmental readiness, emotional needs and the critical bond between caregiver and child. Here's why I do not support cry it out, and what I recommend instead.

Understanding the CIO method

Cry It Out (also referred to as "extinction") is a sleep training approach where babies are left to cry for set periods ­– or entirely – without being comforted by a caregiver. The goal is for the child to “self-soothe” and fall asleep independently. Supporters argue that CIO can teach babies to fall asleep on their own and improve overnight sleep duration. However, as a holistic sleep coach, I take a broader view – one that centres on the baby’s nervous system, emotional security and parent-child attachment.

The science of infant stress

Research tells us that prolonged, un-responded crying activates the infant stress response system. Cortisol, the primary stress hormone, surges during sustained crying. A landmark study by Middlemiss et al (2012) found that while babies subjected to CIO did eventually stop crying, their cortisol levels remained elevated ­– even when they appeared calm1. In other words, the baby had stopped signalling distress, but the internal stress response had not resolved. This is also known as “learned helplessness.” From a holistic standpoint, this disconnect between external behaviour (quiet) and internal physiology (stress) is deeply concerning. We must ask: are we teaching babies to self-soothe or shut down communication?

Attachment and responsive parenting

Attachment theory, originally developed by John Bowlby and furthered by Mary Ainsworth, underlines the importance of consistent, sensitive caregiving in the first years of life. Secure attachment is built when babies’ needs – including the need for comfort – are reliably met.

Crying is not manipulation. It is communication. When we respond, we help co-regulate our babies' emotions, gradually teaching them how to self-regulate over time.

According to Sroufe et al. (2005), early attachment experiences directly influence the development of emotional regulation and stress response systems2. As a result, ignoring cries may risk disrupting this delicate process.

Decades of developmental research, including findings from the Minnesota Longitudinal Study of Risk and Adaptation, reinforce this point: consistent, responsive caregiving in early life supports emotional resilience and long-term psychological well-being. Meeting a baby's needs – even during night wakings – does more than soothe them in the moment; it builds the foundation for secure attachment, healthier coping mechanisms and lifelong emotional strength.

The role of co-regulation in sleep

Infants are not developmentally equipped to regulate their emotions. Fact. Sleep is a complex biological process that requires the nervous system to shift from alertness to calm. This transition is not always smooth, especially in babies whose circadian rhythms and melatonin production are still maturing.

Dr. Darcia Narvaez, a professor of psychology at the University of Notre Dame, emphasizes that human infants are biologically designed to be in close proximity to caregivers, especially during vulnerable states like sleep. In her work, she notes that early independence around sleep often contradicts evolutionary expectations and can elevate stress responses3.

Long-term considerations

While some studies suggest that CIO does not lead to long-term behavioural harm in all children (e.g. Gradisar et al, 2016)4, it’s important to put these findings into context. Longitudinal studies tend to measure outcomes like behavioural problems or parent-child attachment as assessed by standardised scales – not subtle shifts in emotional attunement or physiological stress coping mechanisms. From a holistic view, “not harmful” is not the same as “beneficial.” Our goal is not simply to avoid harm, but to optimise wellness, connection and trust.

What I recommend instead

In my practice, I take a holistic, responsive approach to infant sleep that may include:

• Optimising sleep environments

• Encouraging age-appropriate routines

• Addressing feeding-to-sleep associations

• Teaching parents about biological sleep needs

• Supporting emotional co-regulation

Rather than forcing independence, we scaffold it gently over time.

Final thoughts

Sleep training is a deeply personal decision, but it's also a reflection of our values around caregiving, communication and development. As a holistic sleep coach, I advocate for approaches that honour both the baby’s biology and the caregiver’s intuition. Crying is not a problem to solve – it’s a message to decode. If we listen with compassion and curiosity, we can uncover the underlying causes of disruption and guide our babies toward truly restorative sleep.

Working with an infant sleep consultant

If you’re looking for a gentle sleep trainer, it’s important to choose someone who truly respects your baby’s emotional needs and doesn’t use CIO techniques in disguise. Many methods marketed as “gentle” still involve leaving babies to cry for long periods, which can be harmful. As an experienced infant sleep consultant I offer guidance rooted in compassion, developmental science and a holistic approach that supports both your baby and your family’s wellbeing.

Book a free discovery call with me today to discuss your unique situation and learn how gentle, responsive sleep coaching can make a positive difference for your baby – and for you.

References

1. Middlemiss, W., Granger, D. A., Goldberg, W. A., & Nathans, L. (2012). Asynchrony of mother–infant hypothalamic–pituitary–adrenal axis activity following extinction of infant crying responses induced during the transition to sleep. Early Human Development, 88(4), 227–232.

2. Sroufe, L. A., Egeland, B., Carlson, E. A., & Collins, W. A. (2005). The Development of the Person: The Minnesota Study of Risk and Adaptation from Birth to Adulthood. Guilford Press.

3. Narvaez, D. (2014). Neurobiology and the Development of Human Morality: Evolution, Culture, and Wisdom. W. W. Norton & Company.

4. Gradisar, M., Jackson, K., Spurrier, N. J., Gibson, J., Whitham, J., Williams, A. S., & Kennaway, D. J. (2016). Behavioral interventions for infant sleep problems: A randomized controlled trial. Pediatrics, 137(6), e20151486.