How Babies’ Brains Develop: Why Early Experiences Matter From Pregnancy Onwards

19 Jan

From the very earliest days of pregnancy, a baby’s brain is developing at an astonishing pace. The experiences babies have — during pregnancy, birth and after birth — play a powerful role in shaping how their brains grow, how they feel about the world, and how they learn to relate to others.

In the UK, there is growing recognition across maternity, health visiting, and early years services that early experiences really matter. The good news is that loving, responsive care — not the perfect gadget or clothing— is what supports healthy development.

Brain Development During Pregnancy

By around 8 weeks of pregnancy, the basic structure of a baby’s brain is already in place. Development then continues throughout pregnancy and into early childhood and is shaped by both biology and experience.

As early as 2 weeks gestation, the foundations of the brain and spinal cord begin forming. And 7 weeks, early brain connections allow babies to make their first movements!

During the second trimester (between 13 and 28 weeks gestation), the brain starts to become more efficient, as nerve pathways are insulated, helping messages travel faster.

Babies are not passive during pregnancy. They are already responding to their environment. Research shows that newborns recognise human faces, respond to emotional expressions, and can recognise the voice of their mother or birthing parent. These early experiences help organise the brain in ways that support later learning and emotional wellbeing.

The First Year: Rapid Growth and Sensory Learning

The first year of life is one of the most important periods for brain development. Areas linked to vision, movement, and coordination grow quickly, helping babies engage more with the world around them.

From around three months, parts of the brain linked to memory develop rapidly. At the same time, areas responsible for language are especially active. Babies’ brains are highly responsive to the language they hear most often — which is why talking, singing, and responding to babies is so important.

By the end of the first year, babies’ brains become more tuned to the sounds of the language spoken at home. This doesn’t mean bilingualism isn’t possible — far from it — but it highlights how strongly early experiences shape brain wiring.

The Second Year: Identity, Emotion and Language

During the second year, many parents notice a big leap in language. Toddlers often understand far more than they can say, and their vocabulary grows quickly.

At the same time, children become more aware of their own feelings, wants, and preferences. This is when toddlers may start asserting themselves more strongly — a normal and healthy part of development as their sense of identity begins to form.

This stage can feel intense for parents, but it reflects a brain that is growing, organising, and learning how to manage emotions and relationships.

Sensory Development: Learning Through the Body

Babies learn first through their bodies and senses. Sensory experiences help them feel safe, curious, and connected.

Smell and taste begin developing early in pregnancy.
Touch develops from around 16 weeks.
From about 24 weeks, the senses develop rapidly — including hearing, sight, taste, and touch.

Babies can sense light and darkness in the womb, and some open their eyes earlier than once thought. Hearing develops steadily, and because sound travels well through fluid, babies hear a rich mix of internal and external sounds.

They hear the steady rhythm of their parent’s body — heartbeat, breathing, digestion — alongside voices from the outside world. By around six months of pregnancy, babies can recognise familiar voices, including partners, siblings, and even family pets.

Speaking, reading, or singing to a baby during pregnancy supports voice recognition and emotional connection.

Emotional Attunement: The “Sixth Sense”

Gentle, calm sounds support a baby’s sense of safety. Louder or sudden noises, like shouting, can be stressful, even in the womb. Studies have shown that some babies physically react to raised voices or sudden loud sounds.

Importantly, babies also respond to their parent’s emotional state. Changes in stress levels affect heart rate, blood pressure, and hormones, which can be passed through the placenta. This does not mean parents need to feel calm all the time. Stress, worry, and difficult emotions are part of everyday life, especially during pregnancy and early parenthood.
What matters most is that babies are supported by care, comfort, and connection. Being soothed and responded to helps babies feel safe, even when things feel hard.

Babies as Active Communicators

Paediatrician T. Berry Brazelton highlighted that babies are not passive recipients of care. Even newborns actively communicate and influence their environment - through crying, gaze, movement, and facial expression.

He identified key developmental tasks babies work through, beginning with physiological regulation — breathing, temperature, and heart rate. Babies who are premature or living in stressful environments may need to devote much of their energy to this task, leaving less capacity for exploration and interaction.

Understanding babies’ cues — changes in colour, breathing, movement, or alertness — helps caregivers respond in ways that support regulation and development.

Understanding Baby States

Newborns typically move through six behavioural states throughout the day:

Deep sleep
Light (active) sleep
Drowsy
Quiet alert
Active alert / fussing
Crying

Quiet alert is the optimal state for interaction and bonding. Crying is not a failure; it is a baby’s way of asking for help when they cannot regulate alone.

Learning to recognise these states helps parents respond with confidence and compassion.

Engagement, Play and Connection

When babies are regulated, they actively seek connection. Engagement cues include eye contact, smooth movements, smiling, and reaching.

Play and interaction create optimal environments for brain development:

New skills emerge
Neural pathways strengthen
Social connection deepens
Future learning becomes possible

This cycle underpins healthy emotional and cognitive development.

How Interaction Shapes Development

The CARE-Index highlights how parent–infant interaction evolves over time:

0–3 months: Physiological regulation
3–6 months: Turn-taking
6–9 months: Shared play
9–12 months: Reciprocal communication
12–15 months: Language-rich play

Each stage builds on the last. Some disruptions are normal — what matters is noticing and repairing them. Through repeated experiences of being seen, soothed, and responded to, babies learn that their communication matters.

FAQs: How Babies’ Brains Develop

Q1. Why are early experiences so important for baby brain development?

Early experiences shape how neural connections form. Responsive care, emotional safety, and sensory input help build strong foundations for learning and wellbeing.

Q2. Can babies feel emotions before they are born?

Babies respond to physiological changes linked to a parent’s emotional state, which can influence their stress and regulation systems.

Q3. Does talking to my baby in the womb really help?

Yes. Babies recognise familiar voices and rhythms before birth, and repeated exposure supports voice recognition and emotional connection.

Q4. What is the quiet alert state and why is it important?

Quiet alert is when babies are calm, awake, and attentive. It’s the best time for bonding, play, and interaction.

Q5. What if my baby cries a lot — am I doing something wrong?

No. Crying is communication. Babies need support to regulate, and responding builds trust and emotional security.