The brain contains 100 billion neurons at birth.

Infant & Toddler Brain Development

by Karen Hellesvig-Gaskell

Your little one's brain miraculously begins to take shape just three weeks after conception. The brain, like all areas of a child's development, undergoes amazing growth from infancy to age 3. A newborn's tiny brain weighs less than 1 pound, according to the University of Georgia; that's about 25 percent of its adult weight. Both genetics and the environment assume important but very different roles in the brain development of infants and toddlers.


Your baby’s genetic makeup determines her brain's blueprint that's used to form nerve cells, which connect different areas of her brain. For example, the cerebellum helps your child make voluntary movements, such as picking up a toy or developing the balance needed for walking, skipping and jumping. The frontal lobe has numerous functions, such as remembering and learning language. The environment steps in to customize the brain’s genetic profile. Tweaking the brain helps a child more easily adjust to her family's surroundings or way of life -- whether it’s growing up on a farm where playmates are a rarity or attending child care or preschool in a big city with many available peers.


An infant is constantly making impressive cognitive strides. A 4- to-7-month-old has already figured out cause and effect. For example, your infant knows that specific behaviors like crying are quite effective at getting your attention or that smiling makes you smile back. An 8- to 12-month-old understands that Mommy still exists even when she can't see her at the moment. When she notices her teddy bear isn’t in her crib, she knows it’s around somewhere.


Toddlers find meaning in events, objects and words. For example, a 2- to- 3-year-old understands that Grandma's birthday is a special occasion, Mommy's big spoon helps stir cake batter to make a birthday cake, and "later" means "not right now." Hand-eye coordination and motor skills, like running and climbing or scribbling with a crayon, also improve during the toddler period.


Turning off the TV may be in your toddler's best interest. Children up to age 3 learn better from real-life experiences than they do from a computer or TV screen, especially when it comes to language. A toddler hears a parent say about 940 words an hour when the TV is off. That number plummets to 770 when the TV is on, even when no one is watching, points out the American Academy of Pediatrics. Hearing fewer words, over time, means your toddler isn't learning as much as he could be.


A child’s brain has grown to 80 percent of its adult weight (approximately 3 pounds) by age 4, notes the University of Georgia. But brain development is a lifelong process in many ways. It’s forever restructuring itself to meet the ever-changing challenges that life presents. However, once a brain is fully developed, its structure and function stabilize, although learning continues throughout life.

About the Author

Karen Hellesvig-Gaskell is a broadcast journalist who began writing professionally in 1980. Her writing focuses on parenting and health, and has appeared in “Spirituality & Health Magazine" and “Essential Wellness.” Hellesvig-Gaskell has worked with autistic children at the Fraser School in Minneapolis and as a child care assistant for toddlers and preschoolers at the International School of Minnesota, Eden Prairie.

Photo Credits

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