SleepTraining

Sleep Training, Defined: What Parents Are Actually Teaching (and What They’re Not)

When to Start Sleep Training ?

Short Answer:

Most babies are developmentally ready for sleep training between 4 and 6 months of age, when circadian rhythms stabilize and the ability to self-soothe begins to emerge.

Why Timing Matters

Sleep training is less about the method and more about developmental readiness. Starting too early can lead to excessive crying and failure. Starting too late can create deeply ingrained sleep associations that are harder to change.

Timing affects:

  • Emotional regulation

  • Night waking frequency

  • Speed of results

  • Parental consistency

(See also: What Is Sleep Training?)

Biological Signs a Baby Is Ready

A baby may be ready for sleep training when most of the following are true:

  • Sleeps longer stretches at night (3–4 hours)

  • Shows predictable sleep-wake cycles

  • No longer needs frequent night feeds

  • Can briefly self-soothe (hands, sucking, repositioning)

These signs typically appear between 4–6 months, but variation is normal.

(Read next: Sleep Training at 4–6 Months)

What Happens If You Start Too Early

Before 4 months, sleep is still dominated by reflexes and immature neurological patterns.

Starting sleep training too early may result in:

  • Increased stress (for baby and parent)

  • No lasting improvement

  • Confusing sleep signals

This is why most evidence-based approaches recommend waiting.

(Related: Is Sleep Training Harmful?)

What Happens If You Wait Too Long

Waiting beyond 9–12 months is not harmful — but it often requires:

  • More gradual methods

  • Greater emotional support

  • Longer adjustment periods

Sleep associations become stronger with age.

(Read next: Sleep Training at 7–9 Months)

Age Windows at a Glance

  • 0–3 months: Not recommended

  • 4–6 months: Ideal starting window

  • 7–9 months: Still effective, more resistance possible

  • 10–12 months: Works, but consistency is critical

  • 12+ months: Toddler strategies required

(Deep dive: Toddler Sleep Training)

Most Parents Also Struggle With

  • Sleep regressions vs readiness

  • Night wakings after starting training

  • Teething during the training window

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