Sleep Training Methods: What the Research Actually Says

As a pediatric nurse practitioner, I hear the same questions from exhausted parents every day: “Should I let my baby cry it out?” “Will sleep training damage our bond?” “Which sleep training methods actually works?”

The internet is full of passionate opinions about sleep training, but what does the actual research tell us? Let’s separate evidence from emotion and look at what science says about the most common sleep training approaches.

The Ferber Method: More Than Just “Cry It Out”

What It Actually Is

Dr. Richard Ferber’s approach, often called “progressive waiting” or “graduated extinction,” involves putting your baby down awake and returning at predetermined intervals to briefly comfort them. Despite popular belief, it’s not about leaving your baby to cry alone indefinitely.

The method typically follows this pattern:

• Night 1: Check at 3, 5, then 7-minute intervals
• Night 2: Check at 5, 10, then 15-minute intervals
• Night 3: Check at 7, 15, then 20-minute intervals

What the Research Shows

Multiple randomized controlled trials have demonstrated the Ferber method’s effectiveness:

• A 2006 study in Sleep found that 94% of infants showed significant improvement in sleep consolidation within one week
• Research published in Pediatrics (2016) showed that graduated extinction reduced bedtime crying by an average of 43 minutes and night wakings by 50%
• Long-term studies indicate these improvements typically maintain for at least six months

Important clarification: Ferber himself emphasizes that his method isn’t appropriate for all families or all sleep issues. Medical causes of sleep disruption should always be ruled out first.

Full Extinction: The “True” Cry It Out Method

The Approach

Full extinction involves putting your baby down awake and not returning until morning (barring safety concerns or illness). This is what most people think of as traditional “cry it out.”

Research Findings

Studies show full extinction can be highly effective:

• A 2012 systematic review found extinction methods reduced sleep problems in 80-90% of treated children
• Average crying duration decreases dramatically by night 3-4 in most studies
• Sleep improvements often occur faster than with graduated approaches

When It Works Best

Research suggests full extinction may be most effective for:

• Babies over 6 months old
• Families who can commit consistently
• Cases where partial checks seem to increase rather than decrease distress

Graduated vs. Full Extinction: What the Data Tells Us

Recent comparative studies reveal interesting insights:

Effectiveness: Both methods show similar success rates (85-95%) for resolving bedtime resistance and frequent night waking.

Speed of results: Full extinction typically works 1-2 nights faster, but the difference is minimal by one-week follow-up.

Parental adherence: Parents are more likely to complete graduated extinction programs, possibly because periodic checking feels more manageable emotionally.

Child distress: Contrary to intuition, some studies suggest graduated extinction may actually prolong crying in certain children who become more upset with brief parental visits.

Who Benefits Most (And Who Should Avoid These Sleep Training Methods)

Best Candidates for Extinction Methods:

• Healthy babies 4-6+ months old
• Families with consistent routines and environments
• Parents who can implement methods consistently
• Cases where sleep issues significantly impact family functioning

Who Should Consider Alternatives:

• Infants under 4 months (neurologically not ready)
• Babies with medical conditions affecting sleep
• Families experiencing major transitions or stress
• Parents unable to tolerate crying without soothing their baby
• Children with certain temperaments who may need gentler approaches (we’ll explore gentle methods like the chair method, pick-up-put-down, and no-tears approaches in our next post)

Red Flags – When to Avoid:

Research indicates extinction methods aren’t appropriate when:

• Baby has reflux, sleep apnea, or other medical sleep disruptors
• Family is experiencing trauma, depression, or major stressors
• Parents cannot commit to consistency due to living situations
• Previous attempts have led to vomiting, extreme distress, or regression in other areas

Addressing Attachment Concerns: What Long-Term Studies Show

Perhaps the biggest worry parents express is whether sleep training methods will damage their relationship with their child. Here’s what longitudinal research tells us:

The Reassuring Evidence:

• A 2012 Australian study following children for five years found no differences in attachment security between sleep-trained and non-sleep-trained children
• Cortisol studies show that while acute stress increases during initial training nights, it returns to baseline levels within a week
• Research consistently shows no increased rates of behavioral problems, anxiety, or depression in sleep-trained children

The Reality:

• Attachment security depends far more on overall responsiveness and caregiving quality than on sleep training methods
• Some studies suggest that improved family sleep may actually enhance parent-child interactions during waking hours
• Cultural factors significantly influence both sleep practices and attachment outcomes

Understanding Your Baby’s Temperament: A Critical Factor

Research consistently shows that a baby’s temperament significantly impacts sleep training success. Consider your baby’s typical responses:

High-sensitivity babies may become more distressed with extinction methods and benefit from gradual approaches or gentle alternatives. These babies often:

• Startle easily at sounds or light changes
• Take longer to settle after stimulation
• Have intense reactions to changes in routine

Persistent babies may cry longer but often respond well to consistent approaches once they understand the new routine.

Adaptable babies typically adjust to most methods relatively quickly, giving parents more flexibility in approach.

Take time to observe your baby’s patterns before choosing between sleep training methods. What works for your friend’s calm baby may not suit your sensitive one, and that’s completely normal.

Making the Right Choice for Your Family

The research is clear: when appropriately applied, both graduated and full extinction sleep training methods are safe and effective for most families. However, “effective” doesn’t automatically mean “right for you.”

Consider these evidence-based factors:

• Your baby’s age, health, and temperament
• Your family’s stress levels and support systems
• Your own emotional capacity for the process
• Whether gentler methods have been tried and failed (stay tuned for our detailed guide on no-cry and gentle sleep methods)

Remember, the “best” sleep method is the one that works sustainably for your unique family situation while keeping your baby safe and healthy.

For a post on the 4-month sleep development phase, check this link

For more information on the Ferber Method, go to this site https://www.sleepfoundation.org/baby-sleep/ferber-method

As always, consult with your pediatric healthcare provider before starting any sleep training program, especially if your baby has underlying health conditions or if you have concerns about their growth and development.