Developmental Milestones

The Only 18-Month Milestones That Matter

By 18 months, developmental milestones may seem to be a thing of the past. They're still there, just few and far between. Here are the ones to keep an eye out for.

Originally Published: 
Toddler pretending her teddy is a patient.

At 18-months-old, or one-and-a-half-years-old, most parents will have a toddler on their hands rather than a baby. And really, in the grand scheme of things, the designation of toddler represents the biggest milestone to be reached at 18 months: the ability to walk. But developmental milestones are a funny thing. Some seemingly precocious kids may be on their feet by 8-months-old. Others might prefer to ambulate in ways other than their own two feet until some 10 months later. And yet, with nearly a year between the onset of independent walking between these two types of toddlers, both could be considered as developing normally. What gives?

The answer is that developmental milestones for 18-month-olds, or any other age for that matter, tend to be contingent on the culture and environment a kid is growing up in. A baby who receives regular leg-strengthening exercises and massage early in life, as is the case in some African cultures, might walk sooner than a child from another culture that is carried all the time. But regardless of when these kids might start walking, they eventually gain the skills they need to toddle around, explore, and interact with their particular environment.

In February 2022, the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics overhauled the pediatric milestone checklist. This process included adding developmental milestones for 15-month-olds and 30-month-olds, and revamping other milestone charts to reflect things most children (75% or more) can do by a certain age. To help parents track milestones on their own, the CDC has released a free Milestone Tracker mobile app, a Digital Online Checklist, and a PDF checklist that parents can download and print.

So there are plenty of developmental milestones your toddler can acquire at 18-months-old, but that doesn’t necessarily mean they have acquired them. So how is a parent to know if there are problems?

It’s far less stressful for parents to consider their child’s history and pace of development rather than worrying if they have hit concrete time-pegged milestones. The developmental milestones that matter at 18 months are less about physical and cognitive skills and more about the developmental trajectory of your particular kid. It’s less about what your child can do by 18 months than it is about skills they’ve missed that may be red flags for developmental problems.

18-Month Developmental Milestone #1: Your Toddler Toddling

At 18 months, most typically developing infants in industrialized nations have started walking without holding onto anything. Those caveats are important. Some children have started walking long ago and some are just getting the hang of it. The onset of walking is likely dependent on a number of factors that will include the kid’s temperament, the opportunities they have been given, and how much encouragement they have received.

Red Flags: An 18-month-old who appears to be unable to stand or support themselves for long despite some effort may have deeper developmental issues. Look for signs that your toddler is favoring one side overwhelmingly or seems unable to coordinate their limbs in a way that allows them to get mobile.

What You Shouldn’t Stress About: If your kid isn’t particularly good at walking yet, don’t sweat it. There is no need for your toddler to know parkour at 18 months. If they are taking steps, that’s all that really matters. Some milestone guides will suggest your child should be able to go up and down stairs, but keep in mind, a kid who doesn’t experience stairs on a regular basis probably will not have figured this out. What’s important is that their muscles are strong and they are mobile with an inclination towards getting on their own two feet and taking steps. Some kids might stay cautious cruisers for a bit longer.

18-Month Developmental Milestone #2: Your Toddler Is a Cautious Explorer

Toddling and exploration go hand-in-hand. They have a symbiotic relationship: a desire to explore fuels a push to walk, and walking allows kids to explore more. The way your kid explores will tell you a lot about how they are developing. A child who is interested in things they encounter might point them out to parents and try to name them. Other toddlers might carry the object around and show it to people. Some kids can be directed where and where not to explore by parents.

These behaviors not only show that a toddler is developing physical strength and dexterity, but they also indicate cognitive development through communicating discovery and taking simple direction. Still, a toddler’s abilities to move and communicate are fairly limited compared to their desire. Because their limits are in conflict with their ambitions, don’t be surprised if toddlers tend to melt down in frustration.

Red Flags: Most neurotypical toddlers will return to the safe home base of their parents after exploring independently. If a toddler seems unconcerned about their parents leaving or doesn’t show any interest in them, it may be a sign of developmental delay.

What You Shouldn’t Stress About: Because they want to do more than they’re able to, you can expect a toddler to melt down. You can also expect them to be clingy as they regroup from their exploration. Basically, don’t sweat it if your toddler appears to have big emotions around this time, and maybe cut them some slack. It’s not easy being a toddler.

18-Month Milestone #3: Your Toddler Starts Pretending

Pretend play really starts kicking off around toddlerhood. You might see your toddler mimicking behaviors they’ve seen you do like looking at a phone. They might pretend to take care of or talk to stuffed animals and dolls, or they might pretend to be another creature. During this pretend play, a toddler will likely display other developmental skills too, like language, laughter, and an ability to connect with other people.

What a toddler pretends is less important than that they are pretending. And parents should make sure kids have plenty of opportunities to exercise their imaginations.

Red Flags: If a toddler looks as if they have lost any abilities they once had, you should see you pediatrician. These kind of regressions may be a sign of developmental issues.

What You Shouldn’t Stress About: Some parents might expect their 18-month-old to be talking, but keep in mind that some kids can get by through non-verbal forms of communication and don’t see the need to speak. If a kid is communicating through gestures, the important part is that they are communicating.

Non-Milestone Moments at 18 Months

Your toddler is likely looking more like a little kid than a baby. This can be an emotional time for parents. You can also look forward to your toddler’s molars coming in. Finally, look for your toddler to start losing some naps around this time.

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