9 to 12 Month Infant Development

In the first year, infants move through several developmental changes 1. Between the ages of 9 and 12 months, your baby is moving further away from infancy and closer to the toddler stage. This early childhood development is marked by milestones, which are sets of skills or age-specific tasks, that most children are able to do at a specific age range 1.


Between 9 and 12 months of age, your baby is rapidly developing fine and gross motor skills. It is at this point that your baby will become more physically active than at previous stages. Your baby will attempt to crawl, stand alone, and walk while holding onto a support such as the sofa or a table. He will also throw things. He will also try to feed himself, using his thumb and forefinger to pick up food, and may use the index finger to point. While playing, your baby may bang toys together or turn the pages of a board book.


Infants between the ages of 9 and 12 months are usually chatty, although they may not say any clear words just yet. Your baby may babble and will pay close attention to faces, voices and sounds. This babbling may take on a conversational tone as your baby imitates your speech and sounds. She may respond to simple requests and to words like “no” or her own name. Your baby may communicate by shaking her head and may say simple words like "Mama" or "Dada" by 12 months of age.


Your baby’s brain is developing its problem-solving skills between 9 and 12 months, and curiosity is extremely high. Infants examine small objects, will try to imitate toys, and enjoy searching for things that are hidden. Between 9 and 12 months of age, your infant’s memory is still short, but he uses repetition to learn and will experiment with objects and sounds repeatedly, and observe those around him intently. This is the age where dropping a toy from the high chair becomes a favorite game, as your baby learns the concept of object permanence. You may also find your baby mimicking the things that you do every day, such as brushing hair, talking on the phone, or pushing buttons on the remote control. You may find your 9- to 12-month-old also looks at pictures or books and can point to certain objects when they are named.

Social Emotional

Social and emotional development of 9- to 12-month-old babies involves your baby’s ability to distinguish familiar people from strangers and establishing relationships or bonds. It is not uncommon for previously outgoing infants to become shy or fearful around strangers during this time. Your baby will show several other emotions as well, such as:

  • happiness
  • sadness
  • irritation
  • anger
  • surprise

She may begin to notice when you go away and when you return. It is normal for babies to cling to parents during this time, as they establish special relationships and develop their own personalities. Games like peek-a-boo are favorites, and they demonstrate to your infant that although she may not be able to see the people she depends on, she is still safe because they will return. Communicate and encourage your baby to explore by making her feel safe and secure. For example, when you leave the room, talk to your baby from the other room to reassure her that she is not alone.