Twin Toddler Development Milestones: What to Expect Between Ages 1 and 3
Somewhere between their first and second birthdays, I realized my babies weren’t babies anymore.
My son was climbing anything that stayed still long enough. The couch, the coffee table, the kitchen chairs. If there was something to climb, he was already halfway to the top before I could blink. Meanwhile, my daughter wanted me to witness every new accomplishment. Whether it was a jump, a dance move, or a new word, she always seemed to be asking, “Did you see that?”
Watching them grow into toddlers has been one of my favorite stages so far because their personalities have become impossible to miss. Even though they’re twins, they couldn’t be more different in some ways, and that’s reminded me that development isn’t about keeping score. It’s about watching two little people become exactly who they’re meant to be.
Between ages 1 and 3, your twins will learn to walk, run, climb, talk, solve problems, and explore the world in entirely new ways. One of the biggest questions parents ask during this stage is whether their twins should be reaching milestones at the same time.
The short answer is no.
Even identical twins develop at their own pace. One may take off running while the other is busy building their vocabulary. Those differences are often completely normal.
Understanding what to expect during toddlerhood can help you celebrate each child’s progress while recognizing when it may be time to ask your pediatrician for additional guidance.
Do Twins Reach Milestones at the Same Time?
Usually not.
Twins share birthdays, homes, and many of the same experiences, but they’re still two unique children with their own strengths, interests, and developmental timelines.
It’s common for one twin to:
Walk before the other
Talk earlier
Develop fine motor skills more quickly
Become potty trained sooner
Show different interests and personalities
I’ve seen this firsthand in my own home. My son has always been fearless physically. He hit many of his gross motor milestones without looking back, and honestly, it can be a little terrifying. I’m constantly reminding myself that furniture is apparently his personal jungle gym.
My daughter has taken a different path. She’s our little communicator. If she doesn’t know the word she wants, she’ll happily fill the conversation with toddler gibberish and keep talking anyway. Nothing slows her down.
Instead of comparing your twins to one another, try to look at each child individually. Every new skill they learn is another step in their own unique journey.
Corrected Age for Premature Twins
If your twins were born prematurely, your pediatrician may use their corrected age when evaluating development during the first two years of life.
Corrected age adjusts for the number of weeks your babies were born before their due date.
For example, if your twins were born eight weeks early and are 12 months old, their corrected age would be about 10 months.
Using corrected age often provides a more accurate picture of development for babies born prematurely. Corrected age is commonly considered through about age 2, although your child’s healthcare provider can guide you based on how early your babies were born and their individual development.
Development Between 12 and 18 Months
Development changes quickly during this stage. The skills below are examples of milestones you may see emerge across this age range. They are not a checklist of skills every child should have at 12 months.
During this stage, many toddlers begin to:
Gross Motor Skills
Walk independently
Climb onto furniture
Pull toys while walking
Begin running
Fine Motor Skills
Stack a few blocks
Turn book pages
Use a spoon with help
Scribble with crayons
Language
Say several simple words
Follow simple one-step directions
Point to familiar objects or things of interest
Respond to their name
Social and Emotional Development
Show affection
Begin simple pretend play
Experience separation anxiety
Show increasing independence
Development Between 18 and 24 Months
There can be a huge amount of development between 18 months and a second birthday. These are examples of skills that may emerge during this period, not a checklist every toddler will complete on the same timeline.
Many toddlers begin to:
Gross Motor Skills
Run
Kick a ball
Walk up stairs with assistance
Fine Motor Skills
Stack blocks
Turn pages in a book
Begin using a spoon more independently
Language
Begin combining two words
Name familiar objects
Follow simple instructions
Understand much more language than they can say
This has been such a fun stage in our house. My daughter loves sitting on my lap to play “Row, Row, Row Your Boat.” She grabs my thumbs like they’re the oars, deciding exactly how fast we’re supposed to row. If she rows slowly, I sing slowly. When she suddenly speeds up, I have to keep up with her. And when we get to “don’t forget to scream,” she throws her hands on her face and lets out the biggest scream she can manage.
It’s become one of those little moments I’ll never forget.
Social Development
Play alongside other children
Copy adults and other children
Show a wider range of emotions
Test boundaries and become increasingly independent
Something else changed around this age that completely melted my heart. For the longest time, my twins mostly played beside each other. Then, a couple of months ago, they actually started playing together.
Now my daughter wakes up looking for her brother before she’s even fully awake.
“Bubba!”
They spend half the day chasing each other through the house and the other half playing peekaboo across their car seats. Watching their relationship grow has been one of my favorite parts of toddlerhood.
Development Between 2 and 3 Years
Development continues rapidly between the second and third birthdays. Some of these skills appear closer to age 2, while others may not emerge until closer to age 3.
During this stage, many toddlers begin to:
Gross Motor Skills
Jump
Climb confidently
Run with better balance and coordination
Walk up and down stairs with increasing independence
Fine Motor Skills
Draw lines and begin copying simple shapes
Build larger block towers
Turn book pages one at a time
Begin helping with dressing and undressing
Language
Use increasingly complex phrases and short sentences
Ask simple questions
Name more familiar objects and begin learning concepts such as colors
Follow increasingly complex directions, including some two-step directions
Social and Emotional Development
Engage in imaginative or pretend play
Begin learning to take turns
Notice and respond to other people’s emotions
Express a wider range of emotions
Should I Compare My Twins?
It’s completely natural to notice differences between your twins.
I know I have.
One child may be talking nonstop while the other is busy figuring out how to climb onto the kitchen counter. One may crave your attention while the other is perfectly content entertaining themselves.
My son could happily spend an afternoon with a balloon or, surprisingly, the vacuum cleaner. We’re still laughing about the night he woke up at 2 a.m. asking for the “vacvac.” My daughter is almost the opposite. She enjoys playing independently, but she also wants someone celebrating right alongside her. Every accomplishment deserves an audience.
Neither personality is better than the other.
They’re simply different.
Try not to measure your twins against each other. Instead, celebrate the unique strengths each child brings to your family.
When Should I Be Concerned?
Milestone ranges are helpful, but they aren’t meant to replace developmental screening or your pediatrician’s evaluation of your individual child.
Talk with your pediatrician if you’re concerned about either twin’s development, particularly if your child:
Loses skills they previously had
Doesn’t consistently respond to their name
Isn’t using gestures, sounds, or words to communicate as expected
Has significant feeding or swallowing difficulties
Isn’t progressing with movement or walking as expected for their age and individual circumstances
Loses previously acquired language or social skills
Isn’t meeting one or more developmental milestones or you simply feel something isn’t right
You don’t need to wait until you’re certain there’s a problem before asking a question. Developmental screening can help determine whether your child is developing as expected or could benefit from additional evaluation or support.
Early Intervention Can Make a Big Difference
If your pediatrician recommends an evaluation, try not to panic.
Depending on their individual needs, toddlers may benefit from:
Speech-language therapy
Occupational therapy
Physical therapy
Early Intervention services
These services can support children as they develop communication, movement, feeding, social, and everyday skills.
Getting an evaluation doesn’t automatically mean something is wrong. It gives you more information about your child’s development and whether additional support could help.
My RN and Twin Mom Perspective
As a Registered Nurse, I’ve learned that child development is rarely a straight line. There is a wide range of what is considered typical, and every child reaches milestones in their own time.
As a twin mom, I’ve learned something just as important. Milestones tell us what our children are learning, but their personalities tell us who they’re becoming.
My husband and I joke that we’re constantly living through “Freaky Friday” because our twins seem to switch personalities every few months. Our daughter was our more challenging newborn during witching hour, then became incredibly easygoing while her brother became more demanding. Later they switched again during teething, and then again. Every stage has reminded us not to assume today’s challenges or today’s strengths will last forever.
Some days I look around my house, watch two toddlers running in opposite directions, and my biggest thought is simply, “Oh my goodness… there are two.”
Toddlerhood is busy, loud, unpredictable, and wonderfully exhausting. Try not to get caught up comparing timelines. Celebrate each milestone, enjoy the little moments in between, and remember that you’re raising two unique little people, not trying to create identical ones.
🗣️ Dr. Judy’s Perspective
One of the biggest misconceptions parents hear is to simply “wait and see” if a child catches up. While every child develops at their own pace, early intervention can make a tremendous difference when extra support is needed.
An evaluation doesn’t automatically mean something is wrong. It provides valuable information about your child’s strengths and whether they might benefit from additional support.
The earlier children receive help, the more opportunities they have to build important communication, learning, and social skills during a critical period of development.
Remember, asking questions and seeking an evaluation is one of the best ways to advocate for your child.
💛 Twin Parent Tip Try to spend a little one-on-one time with each twin whenever you can, even if it’s only 10 to 15 minutes. Individual time helps you notice each child’s unique strengths, interests, and developmental progress without automatically comparing them to their sibling.
Frequently Asked Questions
Is it normal for one twin to talk before the other? Yes. It’s very common for one twin to develop language earlier than the other. Twins are two individual children, and their communication skills don’t have to develop at exactly the same pace.
Should identical twins reach milestones at the same time? No. Even identical twins are unique individuals and often reach developmental milestones at different times.
Does prematurity affect toddler milestones? Yes. For children born prematurely, corrected age may be considered when evaluating development during approximately the first two years.
When should I ask about speech therapy? If you have concerns about your child’s communication, you don’t have to wait until they’re significantly behind to bring it up. Talk with your pediatrician about your concerns. They may recommend developmental screening or a speech-language evaluation.
Related Guides
Managing Big Feelings and Toddler Tantrums
Teaching Twins to Share
Biting, Hitting, and Aggressive Behavior
Twin Toddler Sleep
Potty Training Twins
Preparing Twins for Preschool
References
Centers for Disease Control and Prevention (CDC). CDC’s Developmental Milestones.
American Academy of Pediatrics (AAP). Developmental Surveillance and Screening.
HealthyChildren.org, American Academy of Pediatrics. Developmental Milestones.
American Speech-Language-Hearing Association (ASHA). Communication Milestones.
U.S. Department of Education. Early Intervention Services for Infants and Toddlers.
Medical Disclaimer This article is for educational and informational purposes only and should not replace medical advice, developmental screening, diagnosis, or treatment from your child’s pediatrician or another qualified healthcare professional.
Development varies from child to child, and milestone ages represent general developmental expectations rather than an exact timeline for every child. If you have concerns about either twin’s development, including loss of previously acquired skills, talk with your child’s healthcare provider.
