Major Milestones in the Biological Development of Children

By Samantha Hanly
Holding up her head is a major developmental milestone.
Holding up her head is a major developmental milestone.

Developmental milestones are skills, tasks and abilities that typical children can do within a specific age range. Pediatricians use milestones to help check how their patients are developing. It is important for parents and caregivers to remember that each individual child develops at his own pace, and reaching a milestone later than others is not necessarily abnormal. Parents should never be afraid to ask their pediatricians any question about how their child is growing.

Six Months

By the time your baby is 6 months old, she will likely be able to hold up her head when placed on her tummy, and also roll over from front to back and back to front. She knows the faces and voices of her caregivers, and will smile back when greeted with a smile. Children this age are able to reach and grab objects, and they are prone to explore by putting items in their mouths. Babies who have reached these developmental milestones must be supervised carefully so they don't choke.

One Year

By 1 year of age, your baby can sit up by herself and feed herself foods such as small crackers or cereal. She is most likely creeping or crawling; some babies walk at 1 year old, but it is normal not to start walking unassisted for another few months. A 1-year-old child understands some spoken language, and might try to imitate specific words. She probably has a favorite toy or blanket, and might experience separation anxiety when a caregiver leaves the room.

18, 24 and 36 Months

Around 18 months of age, your child becomes a toddler. A toddler is much more independent than a baby because she crawls quickly, is able to pull herself up unassisted, and by 18 months she is walking. By 24 months, she is feeding herself efficiently but in a messy manner. A child this age will show you affection. Her language comprehension is ahead of her ability to form words, but she will try to speak. Between 24 and 36 months of age, she will be able to sit in a child-size chair, hold a crayon and color. She will likely move her entire arm while coloring, so she will need large pieces of paper and lots of space. Toilet training usually happens at this time, however, children this young often have accidents.

3 to 5 Years

Most 3-year-olds have the gross motor skills necessary to walk up and down stairs, throw a ball and stand briefly on one foot. Your 3-year-old probably enjoys swinging on the swing set and peddling a tricycle. She most likely pays close attention when you read to her, and plays "make believe" during her quiet play time. At 4 years of age, she can run more gracefully than before, and might be proficient in bathroom use. Your 4-year-old has reached the developmental milestone of fine motor coordination. She can use scissors to cut paper, mold clay, and hold a crayon to draw shapes without moving her arm in wide arcs. By 5 years of age, you should see improvement in both fine and gross motor development and milestones. She can write letters and numbers, and skip, jump and tumble. At 5 years of age, you will notice whether she is right- or left-handed.

About the Author

Samantha Hanly is an organic vegetable gardener, greenhouse gardener and home canner. She grows a substantial portion of her family's food every year. After receiving her bachelor's degree, Hanly embarked on a career teaching dramatic arts, arts and crafts, and languages. She became a professional writer in 2000, writing curricula for use in classrooms and libraries.