As a mother lifts her baby up to play, she wonders if her little one is reaching the typical developmental stages of a baby.

Leaps in the Developmental Stages of a Baby

“Is my baby normal?” This is a common question that parents (especially new parents) ask regarding the general developmental stages of a baby. We are always eager to check if our babies’ changes are age-appropriate and it’s difficult to resist comparing our kids to each other. Try to remember that all babies are different and the development stages of a baby can be just as unique as your little one. Below are the developmental milestones, from physical to motor, that generally occur during the baby’s first year.

Physical Development


During the first 6 months, the average infant has a weight gain of 2 lb per month. In the next 6 months, weight gain is approximately 1 lb/month. A one-year-old boy typically weighs 10 kg while a girl weighs 0.5 kg less than that.


A baby’s height increases by 50% from his/her birth length. The growth is more obvious in the trunk than the legs during the early months. By the end of the first year, it’s common that an infant’s legs may still appear short and bowed.


The first deciduous tooth or baby tooth usually starts to show by the 6th month. Every month after that, a new tooth emerges. Some babies, however, are born with teeth. These are referred to as natal teeth.

Sensory Development

A one-month-old baby can only see an object that’s right in the middle of their field of vision. They can’t follow objects past that midline. A major milestone in the development of a baby’s eyesight is when she starts following objects with her eyes; it is called binocular vision. To stimulate your baby’s vision, start making eye-to-eye contact right after birth.

A noticeable sign of a baby’s hearing awareness is when the child quiets suddenly due to a distinctive sound. This starts at the first month of life. By the 5th month, your baby should be able to locate the sound downward and at the sides. Locating the sound above is added during the 6th month. At 12 months, the baby can easily detect sounds in all directions.

Language Development

By the end of the first month, a baby starts making cooing sounds. By the 2nd month, most babies communicate through different cries – one for when she’s wet, one for when she’s hungry, and one for when she’s sleepy.

At 3-4 months, a baby starts to squeal, coo, and make gurgling sounds. A baby starts saying ‘goo-goo’ and ‘gah-gah’ by the 5th month. A baby can imitate sounds and say simple vowels by the 6 and 7th month. At 9 months, start listening for your baby’s first words.

Usually, babies say “da-da” first than “ma-ma.” This is because they have an easier time pronouncing the former than the latter. It has nothing to do with favoritism. We’re pretty sure your child loves you both equally.

At one year of age, babies can usually say two simple words that have meaning such as “love mama”.

Emotional Development

A baby can socialize as early as one month by face recognition. On a similar note, a baby can be pacified best when crying by the one who takes care of her all the time. A social smile (smiles back when a parent smiles or talks to him/her) can be expected from 2-month-old babies.

The most pleasant sound in the world happens by the 3rd month: laughter. During the 4th-5th month, babies will start showing displeasure when a toy is taken away from them. Starting at the 6th month, the baby develops fear of strangers. It heightens at the 8th month hence the term ‘eight-month anxiety’. It diminishes by the 12th month.

Mental Development

According to developmental psychologist Jean Piaget, a baby formally enters the stage of cognizance during the 3rd month; referred to as the Primary Circular Reaction. Babies explore by putting objects in their mouths or by holding them.

By the 6th month, the baby traverses into the Secondary Circular Reaction. She can now understand that it is her hand that is touching the toy.

Object Permanence happens during the 10th month. They know that something exist even if it is not in front of them. You can’t fool your baby when you play peek-a-boo. They know where mommy went and anticipate her return. Cool, right?

Motor Development

A baby can hold her head up when lying on her stomach at 2 months. Head lag fades away by the 5th month and the Moro reflex (a normal reflex that occurs when the baby is startled) at 6th. By the 8th month, a baby can usually sit without support. Crawling happens during the 9th month. By the 10th month, a baby can pull herself to a standing position. She walks with support at 11 months then starts to stand alone and walk by herself by 12 months.

Bear in mind that these developmental stages of a baby are guidelines. They are not general truths; meaning, not all babies experience them. Do not be fazed if your baby is not having the said changes at the exact age. If you are noticing drastic differences in the developmental stages of your baby, that’s when you should talk to your doctor about your concerns. Ultimately, each baby is unique, beautiful and it’s own kind of normal.


At what age/developmental stage did you move your LO to a forward facing seat?

Has anyone tried the Baby Bullet? I want to get one! But I’m unsure about whether it’s even a good product and if the directions with the food are accurate with baby during each monthly stage of their development…

Is there a developmental stage around 9 months that makes LO be more whiny, clingy, having to be held constantly? She used to not be like this & now I can’t get anything done around the house.

My daughter is almost 21 months she has all of a sudden stopped taking her nap during the day. She used to nap once per day from anywhere from 1-3 hours. I’m not sure this is good for her development. Is this just a stage?

Anyone who has young babies, check out the app The Wonder Weeks. Gives you info about each of their stages of development and may help you understand their behavior at certain times. It’s been spot on for us!

Does the 4 month sleep regression/development stage come on gradually or BAM it’s here? What has been your experiences with it and how did you handle it or get through it?

Anyone else going to keep their LO away from tv and electronics the first year or so? I hear the first two years you want to teach them to discover ways to entertain themselves and that its a huge developmental stage.

My LO is 9 months old. Up until a week or two ago she was taking 4.5 (6oz) bottles with breakfast and dinner meals. Now, she only drinks 3 (6oz) bottles a day. The sheet I have says her age should be having 4 (8oz) bottles with meals…

My son will be 6 months old in a week and I was just curious as to what other 6 month olds schedules are like? Eating, naps, sleeping at night, activities during the day, development stages, etc.


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