Brain Development: Growth in the first 5 years



The human brain reaches 95% of its adult size by the time a child turns three years old1.  Although there is consistent growth via neural connections well into adulthood, the structures of the brain are present at birth.  The functionality of the brain changes as children experience the world around them. As a parent, you will notice development of these connections as your child moves from meeting basic needs such as eating and sleeping as a newborn, to a moving, talking, exploring toddler and eventually an independent young child.

The wealth of information available these days on child development is massive and can be all consuming.  Many recommended methods contradict each other and we are constantly charged with determining what is best for our child.  Every child develops at their own rate and faces challenges at different stages.  Your child may walk early, but talk late.  Perhaps separation anxiety is horrible, but sleep habits are excellent.  There isn’t one fix for all of the challenges faced by parents, but if we go back to the basics of how these skills develop, it is easy to feel confident that we are supporting our children the best way we know how.

In the first few years of life, children are building neural connections at 1 million connections per second2.  Every sight, sound, word, touch, and emotion creates a pathway in the brain to build future skills.  The more often a child is exposed to these cues, the stronger the pathway becomes and the more likely it is to become a more permanent connection in the brain.  For example, the more you smile back at your baby when he or she smiles, the more likely they are to build a permanent connection that says smile and your caregiver smiles back! With every interaction and new experience, we are building our child’s brain.

As children continue to grow and experience the world around them, these connections build and build.  At the age of six, a child has the most neural connections of their entire life.  Then a really interesting change begins to happen.  A child’s brain begins to prune, or eliminate connections that are no longer important or regularly used. The brain picks the connections used most frequently and strengthens them to help a child meet daily needs.  This doesn’t indicate that your child isn’t still learning new and exciting things every day.  It simply indicates that brain development over all slows and focuses on necessary skills, emotions, and memories.

For those of you in the thick of the early childhood years, filled with incredible excitement and at times incredible frustration, why is this age so demanding? It’s because of the brain!  A child’s emotional center or limbic system is fully developed, but their prefrontal cortex is developing well into adulthood.  Therefore, they feel and demonstrate every emotion, but impulse control, processing and executive functioning skills are at a minimum. Similarly, in an effort to understand both their independence and their interpersonal relationships, they are consistently testing boundaries and looking for ways to assert control over their environment.  Combined, it is the perfect storm of temper tantrums and personality development that gives us daily (or hourly!) highs and lows.

As a developmental specialist and a parent of a young child experiencing all of these tremendous developments, you’d think I would have a great recommendation for the perfect way to impact your child’s development. The truth is, I’m riding it out with each of you.  Take the highs as they come. Experience the hugs, love and excitement with every new experience and understand that with growth and development come the very challenging, patience-testing meltdowns.  Each second, you are helping to build your child’s brain and you will be amazed at the wonderful person they become.

  1. Giedd J.N., & Rapoport, J.L. (2010). Structural MRI of pediatric brain development: What we have learned and where are we going? Neuron, 67, 728-734.
  2. Center on the Developing Child. (2017) Five numbers to remember about early childhood development. (Brief).

Lauren is a Developmental Specialist at TEIS Early Intervention Provider working with children ages 0-3 and their families. She has a Masters in Education with an Autism Specialization from the University of Pittsburgh and has been working with young children for the past 15 years.  She and her husband, both born and raised in Pittsburgh, now live in the East End with their almost two year old son.