What is the cry it out method (extinction sleep training)

The Cry-It-Out (CIO) method is a sleep training approach where parents allow their baby to cry for a set period without immediate intervention, with the goal of helping them learn to self-soothe and fall asleep independently.

There are two main versions of CIO:

1. Extinction Method – Parents put the baby down awake and do not go back into the room, allowing the baby to cry until they fall asleep.
2. Ferber Method (Graduated Extinction) – Parents check in at increasing time intervals to offer brief reassurance but do not pick the baby up.

What I Don’t Recommend: Full Extinction (where you shut the door and leave the baby to cry with no check-ins). I believe this is unnecessarily harsh and not in line with what we know about infant development and attachment. Babies thrive when they feel secure, and a gradual, responsive approach helps them build independent sleep skills without unnecessary distress.

Instead, I advocate for gentler approaches like my Sleep Lady Shuffle, where parents stay present, provide reassurance, and gradually move away over time. This method is effective while still supporting emotional security.

 

Is the cry it out method safe

Some research supports its safety and effectiveness, while others raise concerns about its impact on emotional well-being. As a sleep coach, I aim to present the research, address concerns, and help parents make informed decisions.

 

 

 

What the Research Says About CIO

 

Studies Supporting CIO as Safe

Research suggests that when used appropriately, CIO does not cause long-term harm and can improve sleep for both babies and parents.

Attachment and Behavioral Development

• A 2020 study in the Journal of Child Psychology and Psychiatry found that occasional CIO use did not harm attachment or behavioral development at 18 months (Bilgin et al., 2020). Babies who underwent sleep training showed no differences in attachment security compared to those who did not.
• Another study found that parents using CIO reported fewer sleep difficulties and less crying over time (Giesbrecht et al., 2020).

Crying Duration and Stress Reduction

• A 1988 study found that infants left to “cry it out” cried less overall within a few nights, indicating they were learning to self-soothe (Rickert & Johnson, 1988).
• Researchers differentiate short-term stress (crying) from chronic stress, suggesting babies adjust to new sleep patterns without long-term harm (Mindell et al., 2006).

Parental Mental Health Benefits

• A 2008 study found that babies who slept better after sleep training improved parental mental health, reducing stress, anxiety, and postpartum depression (Moore, Meltzer, & Mindell, 2008).

Conclusion from These Studies

When applied correctly and consistently, CIO does not harm babies and can improve sleep for the entire family.

 

Concerns and Criticism of CIO

Not all experts agree that CIO is entirely safe or suitable for every baby. Some argue that research may underestimate potential long-term effects.

Potential Risks to Attachment and Emotional Development

• A 2021 commentary in the Journal of Child Psychology and Psychiatry raised concerns that CIO research may not fully capture its impact on attachment and stress regulation (Davis et al., 2021).
• A 1972 study suggested that prolonged, unsoothed crying could increase stress levels, particularly in infants struggling with emotional regulation (Bell & Ainsworth, 1972).

Does Crying Indicate Learning?

• Some experts argue that CIO does not teach self-soothing but instead conditions babies to expect no response from caregivers (Rosier et al., 2020).
• Prolonged distress may cause a cortisol (stress hormone) spike, though research is inconclusive about its long-term effects (Douglas & Hill, 2013).

Parental Comfort and Emotional Toll

• Many parents find CIO emotionally difficult and struggle with the distress it causes them and their baby (Cleveland Clinic, 2021).
• Some sleep experts suggest gentler methods may be equally effective without extended crying (Holliday-Bell, 2023).

Conclusion from These Studies

CIO may not be the right choice for every baby, especially those who are highly sensitive or have difficulty regulating emotions. It can also be challenging for parents who find extended crying distressing.

Kim’s Perspective on CIO Safety

Based on research and experience, here is my professional stance on CIO:

• CIO is not inherently harmful—when done correctly, studies do not show long-term negative effects.
• Full “extinction CIO” (closing the door and leaving the baby to cry all night) is unnecessary—gentler, more responsive methods can be just as effective.
• Consistency is key—inconsistent CIO can increase distress and confusion for the baby.
• Every baby is different—some adapt quickly, while others may struggle with prolonged crying.

Parents do not need to choose between “no crying” and “letting a baby cry for hours.” Middle-ground approaches, like the Sleep Lady Shuffle, encourage independent sleep without extreme distress.

Making the Right Choice for Your Family

If you’re considering CIO, ask yourself:

• Can I stay consistent for at least a week?
• Does my baby adjust well to gradual changes, or do they struggle with big transitions?
• Am I comfortable with some crying, or would a gentler method work better?

For those who find sleep training is not working and full CIO too intense but still want to encourage independent sleep, a gentler, gradual approach may be a better fit. Trust your instincts—every baby and family is different.

 

 

 

 

At What Age Can You Let a Baby Cry It Out?

Most babies are not developmentally ready for sleep training until around six months. At this point, many are capable of self-soothing and can begin to consolidate sleep.

⚠️ What About 4-5 Months? Some babies may be ready for gentle sleep shaping at this age, but full CIO methods are often too abrupt. If you’re considering sleep training before six months, I recommend a modified, gradual approach, such as shorter check-in intervals or staying in the room while reducing involvement over time.

Should a 3-Month-Old Cry It Out?

🚫 No, absolutely not. Three-month-olds are still developing their circadian rhythms and need responsive care. Crying at this age is communication, and a baby this young still requires nighttime feeds and comfort to feel secure.

 

Should you let a newborn cry it out?

No, never. Newborns (0-4 months) need hands-on soothing, frequent feeds, and constant reassurance to build a secure attachment. Sleep training in the early weeks should focus on establishing healthy sleep habits, not CIO.

Instead, I recommend:

• Creating a consistent bedtime routine
• Watchingwake windows to avoid overtiredness
• Encouraging independent sleep gradually (putting baby down drowsy but awake when possible)

How Long Should You Let a Baby Cry It Out?

The duration of crying depends on the method used:

• Ferber Method (Graduated Extinction): Parents check in at timed intervals (e.g., 5, 10, 15 minutes).
• Extinction Method (Full CIO): Baby is left to cry without intervention. This is not a method I recommend. Long, unchecked crying can cause distress, and there are kinder ways to teach independent sleep.

If crying extends beyond 90 minutes, I suggest reevaluating—this may be a sign that CIO isn’t the right fit for your child

Naps and CIO:

Naps are different from nighttime sleep because daytime sleep pressure is lower, making self-soothing harder.

What I Recommend for Naps:

• Keep crying intervals shorter than at night.
• If crying exceeds 30 minutes, pause and adjust the approach. This could mean tweaking wake windows, bedtime routines, or offering a gentler transition.
• If CIO isn’t working for naps after a few days, try a more responsive method (such as sitting next to the crib or using a shorter version of the Shuffle).

Safety and Ethical Concerns:

Is cry it out harmful?

Prolonged, unchecked crying without comfort can be stressful for both the baby and the parents, and it’s important to consider your child’s temperament and age. A gradual, responsive method often works well to minimize stress.

Why is cry it out considered bad by some?

Concerns stem from the emotional distress caused by extended crying. This is why many believe sleep training is bad. However, with methods like the Sleep Lady Shuffle, parents can stay present to offer reassurance while teaching self-soothing.

Effectiveness and Success:

Does CIO work?

Yes, CIO can be effective in teaching babies independent sleep skills. But it’s not the only way.

• CIO works best for parents who can remain 100% consistent.
• If it doesn’t feel right to you, you don’t have to do it! There are gentler alternatives that are just as effective.

Controlled crying vs. cry it out

Controlled crying involves periodic check-ins (as in Ferber’s method), while CIO (extinction) involves no intervention during the crying period

Gentle cry-it-out methods: Approaches like the Sleep Lady Shuffle allow parents to stay close, offering comfort and reassurance without abandoning the baby, helping both parent and child feel supported.

CIO during sleep regressions

I do NOT recommend CIO during a sleep regression!

Sleep regressions (at 4, 8, and 12 months) are caused by developmental changes, and babies often need extra comfort. If sleep falls apart, focus on soothing and reestablishing routines first

 

 

CIO isn’t the only way to teach your baby to sleep. If it works for your family and feels right, great! But if it doesn’t, know that gentler methods—like my Sleep Lady Shuffle—can be just as effective without unnecessary tears.

 

Citations

Bilgin, A., Wolke, D. (2020). Parental use of ‘cry it out’ in infants: no adverse effects on attachment and behavioral development at 18 months. Journal of Child Psychology and Psychiatry.https://pubmed.ncbi.nlm.nih.gov/32155677/

Davis, A. M. B. (2021). Commentary: Does ‘cry it out’ really have no adverse effects on attachment? Journal of Child Psychology and Psychiatry. https://pubmed.ncbi.nlm.nih.gov/33608871/

Giesbrecht, G., et al. (2020). Parental Use of “Cry Out” in a Community Sample During the First Year of Infant Life. Journal of Developmental & Behavioral Pediatrics. https://journals.lww.com/jrnldbp/abstract/2020/07000/parental_use_of__cry_out__in_a_community_sample.8.aspx

Rickert, V., & Johnson, C. (1988). Reducing nocturnal awakening and crying episodes in infants and young children: A comparison between scheduled awakenings and systematic ignoring. Pediatrics.https://pubmed.ncbi.nlm.nih.gov/3340471/

Mindell, J., Kuhn, B., Lewin, D., Meltzer, L., & Sadeh, A. (2006). Behavioral treatment of bedtime problems and night wakings in infants and young children. Sleep. https://pubmed.ncbi.nlm.nih.gov/17068979/

Moore, M., Meltzer, L., Mindell, J. (2008). Bedtime Problems and Night Wakings in Children. Primary Care: Clinics in Office Practice.https://pubmed.ncbi.nlm.nih.gov/18710671/ 

Douglas, P., & Hill, P. (2013). Behavioral Sleep Interventions in the First Six Months of Life Do not Improve Outcomes for Mothers or Infants: A Systematic Review. Journal of Developmental & Behavioral Pediatrics. https://psycnet.apa.org/record/1973-11043-001 

Bell, S. M., & Ainsworth, M. D. S. (1972). Infant Crying and Maternal Responsiveness. Child Development.

Rosier, J. G., et al. (2020). How the Cry-It-Out Method Became Authoritative Knowledge. Journal of Family Issues.https://journals.sagepub.com/doi/10.1177/0192513X20949891