Baby Development Month by Month: What to Expect in Year One

The first year of a baby's life is the most extraordinary period of human development. A person who arrives unable to hold their own head up leaves it walking, communicating, and making you laugh every day. Here is what to expect at each stage.

0 to 2 months

In the first weeks, baby is getting used to the world. They can see about 30 centimetres, which is roughly the distance between your face and yours when feeding. They will begin to track moving objects with their eyes and respond to your voice, turning toward it.

The first social smile usually appears between four and eight weeks and it is one of the most rewarding moments of new parenthood. It is different from the windy grins of the early days because it is responsive, directly connected to seeing your face.

A developmental play gym gives baby something to look at and reach toward during the brief alert periods of early infancy.

3 to 4 months

Baby is becoming more awake and social. They are making cooing sounds, laughing, and beginning to bat at objects intentionally. Tummy time, which should start from birth, is becoming more important now as baby begins to build the shoulder and neck strength needed for rolling.

5 to 6 months

Most babies begin to roll from tummy to back around now, and many will manage back to tummy. Sitting with support is becoming possible. Baby is imitating facial expressions and sounds with increasing accuracy.

This is also usually when solids start.

7 to 9 months

Crawling often begins in this window, though the timeline varies enormously. Some babies skip crawling altogether and go straight to pulling up to stand. Object permanence develops, which is why peekaboo suddenly becomes the funniest thing that has ever happened.

Separation anxiety often peaks around eight or nine months and can be intense. This is a completely normal developmental milestone that shows baby has formed a deep attachment to their caregivers.

10 to 12 months

Most babies are pulling themselves to standing and cruising around furniture. First independent steps might happen anywhere from 9 to 15 months. First words arrive somewhere in this window too, usually mama, dada, or the name of a beloved object.

A safe play space becomes increasingly important as mobility increases.

A note on milestones

Milestones are ranges, not deadlines. Every baby has their own timeline and variation within the normal range is wide. The ones worth flagging to your health visitor are no social smile by eight weeks, no babbling by nine months, no words by 16 months, or any regression in skills already achieved.

Mostly, though, just enjoy watching them become a person. It goes fast.