Children usually progress in a natural, predictable sequence from one developmental milestone to the next. But each child grows and gains skills at his or her own pace. Some children may be advanced in one area, such as language. But they may be behind in another, such as sensory and motor development.
Milestones usually are categorized into five major areas: physical growth, cognitive development, emotional and social development, language development, and sensory and motor development.
Physical growth and development
Most children by age 1:
- Have grown a total of about 10 in. (25 cm) in length since birth and measure somewhere between 28 in. (71 cm) to 32 in. (81 cm) . Somewhere between 9 and 12 months of age, many babies have tripled their birth weight. After their first birthday, babies start gaining weight and growing at a slower pace.
- Have grown in head circumference. (This is the measurement around the top of the head.) The average head circumference of most babies is 18 in. (46 cm) . The soft spots, or fontanelles, of the skull have started to close. But they won't completely grow together until sometime between the 9th and 18th month.
- Still have a "baby" look. Your child's head is large in proportion to the rest of his or her body. His or her tummy sticks out, which can add to an overall "chubby" appearance.
- Get a few teeth. Usually, the first to come in are the two front upper and lower teeth.
Emotional and social development
Most children by age 1:
- Interact mostly with parents and other primary caregivers. They don't show much of an interest in playing with other children. But they do engage in "parallel play." (This means that children play next to or alongside each other but don't interact.)
- Like to "flirt" with parents and other caregivers. They giggle, show off, and seek attention.
- Start to understand permanence—that people and objects still exist even when they are out of sight. Early on, before this concept is learned, some children may still have or seem to have a relapse of separation protest. This means that they feel uneasy and anxious when a parent or another caregiver leaves.
Language development
Most children by age 1:
- Experiment by making different sounds, such as "ptthhh," or repeat sounds, such as "ba-ba-ba-ba." Many toddlers favor practicing the "b" and "d" sounds. They may jabber a long string of sounds with tone and inflection that sound like conversation.
- Can identify each parent, often by name ("mama," "dada").
- Sometimes repeat right away a sound they hear when someone is talking.
- Can say at least 3 words.
- Recognize their own names. They may also look at family members or pets when you talk about them. Typically, babies this age understand some familiar words. But they are still guessing about many other words and their meanings.
Sensory and motor development
Most children by age 1:
- Like to put things in their mouths. This is their way to find out about an object.
- Pull up to a standing position by holding onto furniture or other solid objects.
- "Cruise" (walk while holding on to furniture) or walk on their own.
- Can grasp objects, such as a piece of cereal, with their thumb and second finger ("pincer grasp"). Most children use the pincer grasp by the time they are about 10 months of age.