Quick answer: Dr. Harvey Karp’s 5 S’s method is one of the most evidence-supported and widely used newborn soothing frameworks in pediatric medicine.
Dr. Harvey Karp’s 5 S’s method is one of the most evidence-supported and widely used newborn soothing frameworks in pediatric medicine. It works by replicating the sensory environment of the womb — and when applied correctly and in sequence, it activates what Karp calls the ‘calming reflex’ in newborns. Here’s exactly how to use it.
Why the 5 S’s Work: The Calming Reflex
Newborns have a neurological calming reflex — a set of sensory inputs that, when activated, shift the nervous system from arousal to calm. This reflex exists in all mammals as a survival mechanism: being held, contained, and moved rhythmically by a caregiver signals safety. The 5 S’s are five specific sensory inputs that collectively trigger this response. Used individually, they have mild effect. Used together in a crying baby, the effect is dramatic. Dr. Karp’s research and clinical experience, detailed in The Happiest Baby on the Block, has been replicated in multiple studies showing reduced crying time in colicky infants.
1. Swaddle
Swaddling is the foundation of the 5 S’s — it activates the calming reflex and sets up the other techniques to work more effectively. The swaddle must be snug (arms tucked alongside body) but not restrictive around the hips. Technique: diamond-position blanket, fold down top corner, place baby with neck at fold, bring left side snugly across and tuck, fold bottom up, bring right side across and tuck. The swaddle should feel firm against the arms — a loose swaddle doesn’t activate the reflex and becomes a hazard. Always place a swaddled baby on their back.
2. Side or Stomach Position (for Holding Only)
The stomach-down or left-side position (in your arms — never for sleep) activates intestinal and vestibular reflexes that reduce gas discomfort and trigger calming. Technique: hold baby face-down along your forearm, their head at your elbow, legs straddling your hand, using your forearm to apply gentle pressure to the abdomen. Alternatively, hold baby on their left side with head supported at your shoulder. Critical: This position is for held, supervised calming only — never place a baby on their stomach or side for unsupervised sleep.
3. Shush
Loud, continuous shushing mimics the constant white noise of blood flowing through the arteries near the uterus — a sound the baby has heard continuously for 9 months. The volume needs to match the baby’s crying level — a quiet shush during intense crying is ineffective. Options: mouth-shushing directly near the baby’s ear, a white noise machine at an appropriate volume (under 65 decibels), a hair dryer on low (keep at a safe distance), or a washing machine. The shush must be continuous, not rhythmic. White noise helps mask sudden environmental sounds that can startle a sleeping baby — this is its evidence base for sleep improvement. White noise is not listed as a SIDS-protective factor by NHS, AAP, or the Lullaby Trust; the established protective factors are: back sleeping, firm flat surface, room-sharing without bed-sharing, smoke-free environment, and avoiding overheating. Keep white noise machines at least 1–2 metres from the baby and below 50dB to avoid any risk of hearing damage.
4. Swing
Rhythmic, small-amplitude jiggling triggers the calming reflex via the vestibular system (balance organs in the inner ear). The movement needs to be fast and small — not the slow rocking of a rocking chair, but a rapid (approximately 2–3 per second), small-amplitude jiggle of the head (supported). Technique: support the head firmly, and make small, rapid head-support movements. This is sometimes called the ‘4th S jiggle.’ It should feel intense compared to gentle rocking — but never shake. A swing set to its highest speed setting also works for many babies.
5. Suck
Sucking is the most powerful calming mechanism available to a newborn. Non-nutritive sucking (sucking that doesn’t involve feeding) activates multiple neurological pathways that reduce stress hormone levels. Options: a pacifier (or ‘dummy’), a clean adult finger, or offering the breast (even if not hungry — non-nutritive sucking at the breast is normal). Some parents worry pacifiers will interfere with breastfeeding — the current evidence suggests they can be introduced after breastfeeding is well established (usually 3–4 weeks) without negative effect on feeding.
Frequently Asked Questions
What order should I use the 5 S’s?
Swaddle first — it sets up the others to work. Then add side/stomach position, shushing, and swinging simultaneously if the baby is still crying. Use sucking as a ‘seal the deal’ calming step once the other four have reduced the intensity. In practice, experienced parents often apply all five simultaneously in escalating intensity until the baby calms.
Does the 5 S’s method work for all babies?
It works for most newborns, though effectiveness varies. Babies with organic causes of crying (CMPA, significant reflux, illness) won’t be fully calmed by sensory techniques alone. The 5 S’s work by activating a neurological calming reflex — they work best during normal fussiness and colic. If your baby cannot be soothed by any means and is persistently screaming, contact your pediatrician to rule out medical causes.
When do I stop using the 5 S’s?
The calming reflex gradually fades between 3–4 months as the nervous system matures and babies develop the capacity to self-regulate. Swaddling stops when rolling begins (typically 8–12 weeks). White noise and pacifiers can continue beyond this. Most parents find the 5 S’s are most intensely needed in weeks 4–12 and naturally phase out as the baby’s nervous system develops.
Related Reading
- Newborn crying: decoding the 5 different cries
- Colic in babies: what it is, what helps and what doesn’t
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