Do Babies Need to Learn to Self-Soothe? What the Science of Co-Regulation Actually Says
Babies aren't born with fully mature systems for regulating their emotions, physiology, attention, or sleep. Those capacities develop gradually, and relationships are part of that process.
But co-regulation doesn't mean your nervous system has to perfectly regulate your baby's, either. It is an ongoing process of signaling, responding, adjusting, mismatching, and reconnecting.
Supporting your baby through sleep is not the opposite of helping them develop regulation. And you don't have to regulate perfectly for healthy development to happen.
"But How Will They Ever Learn to Do It Themselves?"
If you feed your baby back to sleep at 2 a.m., will they become dependent on you?
If you pick them up when they cry, are you preventing them from learning to self-soothe?
Underneath these questions is a reasonable assumption: if babies eventually need to regulate themselves, shouldn't we give them opportunities to practice doing it independently?
But that's not really how early regulation develops.
At the same time, I think responsive-parenting conversations sometimes create a different kind of pressure. Parents hear that babies "borrow our nervous systems," and translate that to “we need to remain calm so our babies can regulate.”
Neither story captures the full picture.
What Does Co-Regulation Actually Mean?
Even very young babies participate in regulation. They shift their attention, respond to stimulation, move between states of arousal, and engage in behaviors that help change their state.
But the brain and body systems underlying regulation are still developing.
In a 2026 study, researchers simultaneously measured brain and cardiac activity in three-month-old babies during an attention task. They found real-time coordination between cortical and parasympathetic activity - and that coordination was related to the infants' ability to sustain attention.
In other words, regulation isn't one "skill" a baby either possesses or doesn't. It emerges through developing coordination among the brain, body, attention, emotion, behavior, sleep…and, during infancy, relationships.
That brings us to co-regulation.
It's sometimes described as though a calm parent's nervous system simply makes a baby's nervous system calm. Research suggests something much more dynamic.
In another 2026 study of mothers and their three- to four-month-old infants, researchers measured both behavior and cardiac physiology during face-to-face interactions. Mothers' physiological changes tended to follow their babies' signals by about 10 seconds.
What this tells me is that regulation between parent and baby is more like a conversation:
Baby signals.
Caregiver responds.
Baby responds to the response.
Caregiver adjusts.
And around and around it goes.
Attunement isn't knowing exactly what your baby needs at all times. It's noticing their cues, making your best guess, responding, observing what happens, and adjusting.
Sometimes you'll get it right immediately.
Sometimes you'll try six things before realizing they were tired all along.
It’s all part of the conversation, and as you get to know your baby better and better, that repair and return to synchrony will get easier.
Your Baby Doesn't Need a Perfectly Regulated Parent
Unfortunately, neuroscience can very quickly become another way to make parents anxious.
Caregiver sensitivity does matter. A major 2026 umbrella review of 17 previous meta-analyses found associations between sensitive caregiving and attachment security, cognition, and language development.
But these were associations across repeated patterns of interaction, not evidence that individual moments determine children's outcomes.
Developmental relationships aren't characterized by perfect synchrony, either. Researchers have long described caregiver-infant interaction as moving through periods of match, mismatch, and repair.
You misunderstand a cue, your baby becomes frustrated, you're exhausted and don't respond the way you wish you had, and then you reconnect.
In fact, another 2026 study offers an important caution against assuming that physiological synchrony itself is always beneficial. Researchers found that the relationship between mother-infant synchrony and infant physiology varied depending on maternal anxiety.
Synchrony is not simply a biological scorecard for good parenting.
Development happens in relationship, and development is not a test of parental perfection.
So What Does This Have to Do With Sleep?
A lot, because we often treat three different things as though they're the same:
Sleep regulation involves the biological systems governing sleep and wakefulness.
Sleep consolidation describes sleep gradually becoming organized into longer stretches, particularly at night.
Behavioral sleep independence describes whether a baby falls asleep or returns to sleep without caregiver involvement.
They are related. But they aren't interchangeable.
A 2026 longitudinal study analyzed more than 35,000 hours of infant actigraphy at three, six, and twelve months. Researchers identified approximately 60-minute ultradian rhythms compatible with developing sleep cycles, which gradually lengthened over the first year.
Whether your baby moves through an arousal without signaling, nurses back to sleep, needs rocking, or decides 3 a.m. is an excellent time to practice crawling is a different question from whether their underlying sleep architecture is maturing.
Sleep maturation is not the same thing as sleep independence.
Does Responding at Night Interfere With Healthy Sleep?
We don't have good evidence for such a simple conclusion.
A 2026 longitudinal study examining maternal sensitivity and infant nighttime sleep found some associations between greater caregiver sensitivity and more favorable sleep outcomes, although the findings differed between cohorts and cannot tell us that responsive caregiving causes babies to sleep longer.
What we can say is that responsive caregiving and healthy sleep development are not opposing goals.
Babies can receive help regulating while their own regulatory capacities are developing.
They can be rocked while their sleep architecture matures.
They can nurse to sleep while their circadian rhythms develop.
They can need you differently next month than they need you today.
Supporting development and supporting your baby’s emotional needs are not mutually exclusive.
A Better Question to Ask
Instead of:
"If I keep helping my baby sleep, how will they ever learn to do it themselves?"
Try asking:
"What capacities are still developing here, and is the support we're providing working for our family right now?"
Maybe feeding to sleep is easy and peaceful.
Maybe rocking still works beautifully.
Maybe frequent waking has become completely unsustainable and something needs to change, or maybe your baby suddenly needs less help than they did three weeks ago.
There doesn't have to be a moral judgment attached to any of those possibilities.
You don't have to choose between supporting your baby and supporting their development.
And you certainly don't have to perfectly engineer their nervous system.
You get to learn this baby: Respond. Observe. Adjust. Repair. Try again.
Need More Support?
Understanding what's biologically expected can make infant sleep feel less mysterious, but knowing something is developmentally common doesn't necessarily make exhaustion easier.
My free infant sleep workshop explores how infant sleep actually develops and what families can realistically expect in the early months.
And if sleep is already difficult in your home, my Nurtured Sleep Sessions offer individualized, neuroscience-informed support without assuming that any one approach is right for every family.
The goal isn't perfect sleep. It's understanding your baby, understanding your options, and finding something that works for your family right now.
Further Reading
Parent-Friendly Resources
The Nurture Revolution by Greer Kirshenbaum, PhD
An accessible exploration of infant brain development and the importance of nurturing relationships in early life.
Still Awake by Lyndsey Hookway
A developmentally informed, compassionate exploration of baby and toddler sleep.
Peer-Reviewed Research
Nivison, M. D., Fearon, P., Jenkins, J. M., & Madigan, S. (2026). Annual Research Review: The role of caregiver sensitivity in children's developmental outcomes—an umbrella review. Journal of Child Psychology and Psychiatry, 67(4), 486–507. https://doi.org/10.1111/jcpp.70087
Woelflein, L., Brenner, I., Koenig, J., et al. (2026). Biobehavioral synchrony between three to four months old infants and psychologically healthy mothers during the face-to-face still-face paradigm. Scientific Reports, 16, 24136. https://doi.org/10.1038/s41598-026-65050-1
Aitken, A., Zhang, M., Braren, S., Hume, A., & Brito, N. H. (2026). Dyadic physiological synchrony and maternal anxiety regulate infant autonomic and neural function. Developmental Cognitive Neuroscience, 81, 101794. https://doi.org/10.1016/j.dcn.2026.101794
Aitken, A., Richards, J., Hume, A., et al. (2026). Autonomic and neural activity dynamically couple during infant attention. Communications Biology. https://doi.org/10.1038/s42003-026-10761-4
Pittner, K., Meyer, K., et al. (2026). Maternal sensitivity supports infant sleep: Evidence from two longitudinal prospective cohorts on maternal childhood maltreatment, maternal sensitivity, and infant sleep. European Child & Adolescent Psychiatry. https://doi.org/10.1007/s00787-026-03134-z
Hammad, G., Schoch, S. F., Engelmann, M., et al. (2026). Charting infant sleep cycle development using actigraphy: Longitudinal evidence for ultradian cycle lengthening within the first year of life from 35,000 h of sleep. SLEEP. https://doi.org/10.1093/sleep/zsag161
