Developmental milestones help track a child’s progress, but they often cause parents unnecessary stress. Many factors, like temperament, family dynamics, or prematurity, can affect when milestones are reached.
As parents, we are always curious about our children’s development, and want to make sure they are showing appropriate growth. Developmental milestones form a checklist to help parents and professionals begin to discuss if there is an area of a child’s development that may benefit from extra screening and potential support. It is important to remember that they are designed as guidelines and that there is extreme individual variation among children. It is not possible for anyone to know precisely when or how a child will develop a specific skill.
The Center for Disease Control (CDC) suggests that at least 75% of children would be expected to show that skill by that age. If that hasn’t happened, missing a milestone is more likely to prompt screening and possible referral to early intervention (EI). Prior to 2022, the CDC had placed milestones when at least 50% of children would demonstrate a skill.
It’s important to remember that milestone checklists themselves are not diagnostic, and a child not exhibiting milestone behavior in one setting or by a specific age is often not always of concern.
For example, in a doctor’s office a child may be uncomfortable around strangers (also developmentally appropriate) and not demonstrate a specific behavior, like pointing or clapping on command. There are also many reasons for an infant and young child not to “reach” a milestone at a specified time. For example, a child with an older sibling may verbalize needs slightly later if they have an older sibling communicating for them. Additionally, whether a child is born prematurely can impact the timing at which they show skills. Even temperament can influence the timing at which an infant or child evidences a skill. For example, an outgoing child may start walking earlier than a more introverted one. While not showing behavior on time is often not something to be concerned about, it is always important to check-in with your child’s health provider. That conversation - and a partnership between parents and providers - is important to screen and assess for any support a child may need, and the practical reason that milestones exist.
In the last several decades, we have learned about the profound impact of Early Intervention (EI) services in helping to identify and treat early delays in development. ALL children can benefit from this type of attention and skill building, and the use of EI can prevent longer term delays in childhood. However, screening children for, and allowing them to qualify for state sponsored EI services requires some type of criteria. Enter, milestones. During the first three years of development, milestones are tracked every several months due to the extensive amount of development happening.
Milestones are generally broken up into social/emotional, communication, cognitive, and physical.
Social/emotional milestones include those that involve a child getting to know more about their own and other’s emotions. In the first year, these include such things as early social smiles, preferences for consistent caregivers, showing emotion and learning how to interact and play with others. As children grow older they also include evidencing skills such as empathy.
Communication milestones focus on verbal, as well as non-verbal ways in which a child attempts to interact with others and communicate their needs. In the first year, these include moving one’s gaze toward who is talking and making cooing sounds. As children mature, they include saying their first words and eventually using basic grammar at age five.
Cognitive milestones are centered on a child's ability to learn, solve problems, think and engage in planning. Early milestones include such things as looking for a dropped object and figuring out how to get a toy slightly out of reach. Later milestones include things such as exploring an object to see how it works.
Physical milestones involve large and fine motor skills. Large motor skills usually develop first and involve sitting up, standing, crawling and walking. Fine motor skills involve precise movements such as picking up small objects.
All this to say, milestones can be helpful and allow you to anticipate what’s coming, but they can also be a source of tremendous stress for parents. If your child is consistently missing milestones, you should check in with your child’s healthcare provider. Ask questions about how you can support their growth and development at home, and please remember that every child develops differently. There are many reasons why a child might reach milestones at a different time, and there are many ways to get support.
This article was written by Dr. Erin O’Connor. For more information around milestones, check out our most recent Assembly, Sensory Milestones: What Really Matters with Dr. Allie Ticktin, co-hosted by Esther Park, founder and CEO of Nara Organics and Mariel Benjamin, Cooper’s Director of Groups.