Hannah sent us this one. She says she loved the episode on baby communication, especially the point that babies communicate through lots of channels besides words, and that early verbal ability isn't the same thing as strong communication overall. And it got her thinking about milestones more generally. We put so much emphasis on when babies do things. When they walk, when they talk, how many words they have, when they start reading. Ezra still isn't walking, but he crawls incredibly well, climbs everything, has great balance and dexterity, and just doesn't seem especially interested in walking. He also said quite a few words early, but hasn't kept progressing at some dramatic pace, and has even stopped saying a few things he used to say, while still being extremely good at communicating what he wants without words. She's not worried about him at all. She just wants to know what all these timelines actually mean. So, excluding children with significant developmental delays or medical issues, is there any evidence that doing something earlier within the normal range predicts anything meaningful later in life? Does an early talker become a better adult communicator? Does an early walker have any long-term advantage at all? Does learning to read early set a child up for later academic success? Or do most of these differences simply wash out over time, making a lot of the obsession with early milestones essentially parental competition over things that don't matter much in the long run?
That's a beautifully precise question. And she's put her finger on the exact tension. We have these charts in every pediatrician's office, and parents treat them like a leaderboard.
So today we're going to dig into what the science actually says about milestone timing, and whether the timeline matters at all.
The first thing to understand is what milestones actually are. They were never designed as predictors of future success. They're screening tools. A developmental milestone is a population norm, a statistical statement about when most children do something. The point is to catch the child who is so far outside the norm that something might be wrong. They're red flags for delays, not early indicators of genius.
But somewhere along the way, we turned them into a race. The normal range for walking is nine to sixteen months. That's a seven-month window. First words, ten to fourteen months. And yet parents will panic if a child walks at fifteen and a half months, as if the child has failed an exam.
Right. The normal range is wide because human development is variable. A child who walks at ten months and a child who walks at fifteen months are both developing typically. The question Hannah's asking is whether being at the early end of that range buys you anything later. And the answer, from the research, is mostly no.
Let's look at the two big ones Hannah mentioned. Walking and talking. What does the research actually say?
There's a longitudinal study out of Switzerland, the Zurich cohort, that followed healthy children from infancy into adolescence. Oskar Jenni and his colleagues published it around two thousand thirteen. They looked specifically at the age of independent walking and whether it predicted anything at school age. Cognitive outcomes, motor outcomes. And they found nothing. No association. A child who walked at ten months and a child who walked at fifteen months, when they're seven, when they're ten, when they're fourteen, they're indistinguishable on every measure that matters.
So the early walker doesn't become a better athlete or a better thinker.
Not in the healthy population. The study was specifically designed to exclude children with significant delays or medical conditions. They wanted to know, within the normal range, does timing matter. And it doesn't. There might be a temporary benefit, early walkers get to explore their environment earlier, they can carry things, they can reach things. But those advantages wash out. The brain's developmental trajectory is robust to variation within the normal range. It's not a race because the finish line is the same.
What about talking? Hannah mentioned Ezra said some words early and then stopped saying a few of them. That sounds like the kind of thing that would terrify a first-time parent.
It does, and it's usually nothing. But let me get to the bigger question first. There's a study by Lynne Murray and colleagues, published around two thousand seven, that looked at early language milestones and later cognitive function. They followed typically developing children and found that early first words, early sentence formation, did not predict later cognitive function or language ability. An early talker does not become a better adult communicator. The child who says their first word at ten months and the child who says it at fourteen months, they converge.
So the early talker doesn't become a better adult communicator, and the early walker doesn't become a better athlete. What about the word loss thing? Because that's the one that feels most alarming to parents. Your kid says a word, you hear it, you celebrate, and then they stop saying it.
Transient word regression is common. A toddler will say a word, use it for a week or two, and then drop it while they're consolidating something else. The brain is reallocating resources. It's not a loss in the sense of a skill disappearing forever. It's more like the word goes into storage while the child works on something else, motor skills, social skills, whatever. It usually comes back. The red flag is if the loss is accompanied by a loss of social communication, if the child stops responding to their name, stops making eye contact, stops pointing. That's a different story. But a child who drops a word while still communicating actively through gestures and facial expressions and vocalizations, that's just normal variation.
This connects to what we talked about in the previous episode, the gestural communication finding. Hannah mentioned it. The research showed that lots of gestural communication at around fourteen months was associated with better communication skills later. And that's a different channel. It's not just earlier words. It's a broader communicative repertoire.
Gestures are not just a precursor to words. They're a communication system in their own right. A child who points, who waves, who shakes their head, who uses facial expressions, that child is building the infrastructure for communication. The words are just one output. So a child like Ezra, who Hannah says is extremely good at communicating what he wants without words, is doing exactly what the research would suggest is valuable. He's building the communicative foundation. The words will come.
There's also a developmental trade-off thing going on. A child focused on motor skills may deprioritize language temporarily. Ezra crawls incredibly well and climbs everything. His brain is spending its energy on that. The language will catch up.
That's the dynamic allocation model. The brain has limited resources, and it allocates them where they're needed. A child who is intensely focused on motor exploration may have less energy for language production at that moment. But it's not a deficit. It's a prioritization. And it shifts. The child who was all motor at fourteen months may become all language at eighteen months. The systems interact.
So if early walking and talking don't predict much, what about reading? That's the one parents get most competitive about. My kid was reading at four. Oh yeah, mine was reading at three and a half.
Reading is where the research gets more interesting, because there is a correlation between early reading and later academic achievement. Children who read early do tend to do better in school. But the correlation is confounded. Heavily confounded.
Confounded by what?
Socioeconomic status, parental involvement, and IQ. Children who read early tend to have parents who read to them a lot, who have books in the house, who value education. They tend to come from families with more resources. And they tend to have higher IQs. When you control for those factors, the predictive power of early reading age diminishes significantly. It's not the early reading itself that causes later success. It's the environment that produces both the early reading and the later success.
So the early reading is a symptom, not a cause.
That's the washout hypothesis in a nutshell. Most differences in milestone timing within the normal range wash out by school age or adolescence. Late walkers catch up. Early talkers don't become better communicators as adults. Reading age has little long-term impact once you account for the environment. The thing that matters is the quality of the environment, not the timing of the milestone.
Which brings us to the uncomfortable question. If the timing doesn't matter, why do we care so much?
Because it's measurable. Because it's visible. Because it's something to compare. Parenting is an exercise in radical uncertainty. You don't know if you're doing it right. You don't know if your child will be okay. So you grasp at anything that looks like data. And milestones are data. They're concrete. They're charted. They're discussed in mommy groups and daddy groups and pediatrician visits. They give you the illusion of control.
And the illusion of competition.
Yes. The parental competition angle Hannah mentions is real. It's not just harmless social comparison. It can be actively harmful. The pressure to hit milestones early leads to over-scheduling, to stress, to misinterpreting normal variation as deficit. Parents start seeing their child as behind when the child is simply on a different schedule. And that anxiety transmits to the child.
There's a knock-on effect here. The anxiety about milestones isn't just unpleasant, it changes behavior. Parents who are worried about language might talk to their child differently. They might pressure the child to perform. They might stop following the child's lead and start drilling. And that can actually interfere with the very development they're trying to promote.
The concept that's useful here is developmental cascades. Individual milestones don't predict outcomes, but the quality of caregiver-child interaction does. Responsive communication, following the child's lead, responding to their gestures and vocalizations, that's what builds language and cognitive skills. Not the timing of the first word. Not the age of first steps. The interaction quality.
So what actually predicts long-term success? If it's not early walking or talking or reading, what is it?
Executive function. Social-emotional skills. A supportive environment. The ability to regulate attention, to manage frustration, to persist at difficult tasks. These are the skills that predict academic and life success. And they're built through responsive, supportive caregiving, not through hitting milestones on a schedule.
Executive function is a better predictor than reading age?
In most longitudinal studies, yes. The child who can sit with a difficult puzzle, who can manage frustration, who can follow multi-step instructions, that child is set up for success. And those skills develop through play, through interaction, through the kind of responsive caregiving that doesn't care whether the child walked at ten months or fifteen.
So Hannah's instinct is right. She said she's not worried about Ezra, and the science backs her up. He's communicating actively, he's crawling and climbing, he's building the foundation. The fact that he's not walking yet, or that he said some words and dropped them, that's just variation.
Yes. They're reading to their kids, they're talking to them, they're playing with them. The very thing they're doing because of anxiety is the thing that actually matters. The anxiety is unnecessary, but the behavior it produces is often beneficial.
The anxiety is the price you pay for the behavior.
Right. But the anxiety itself can be corrosive. It can make you see your child as a project rather than a person. It can make you miss the actual communication that's happening because you're waiting for the word count to hit some number.
There's a distinction Hannah drew that I want to sit with. She said Ezra is extremely good at communicating what he wants without words. That's receptive and expressive communication through non-verbal channels. And she's noticing it. She's not just waiting for the words. She's seeing the communication that's already there.
That's the responsive caregiver. The parent who notices the pointing, the reaching, the facial expressions, and responds to them. That's the interaction quality that predicts good outcomes. She's doing the thing that matters, and she's doing it without the anxiety that the milestones are supposed to produce.
Let me ask you something from the pediatrician side. When parents came to you worried about milestone timing, what did you actually look for?
I looked for the red flags. Is the child losing skills across multiple domains? Is there a loss of social engagement? Is there asymmetry, like using one side of the body much more than the other? Those are the things that warrant investigation. A child who is fourteen months and not walking but crawling well and climbing and showing good balance, that's not a red flag. That's a child who is working on other things.
And the parents who came in with a chart and a list of dates?
They were usually the parents of children who were developing perfectly normally. The chart was the problem, not the child.
So the charts are useful for screening, but they become a source of anxiety when they're used as a leaderboard.
Yes. And the charts are getting more elaborate. There are apps now that track every milestone, every word, every step. They gamify development. They send you notifications when your child is approaching the edge of the normal range. It's the industrialization of parental anxiety.
Which is a whole other episode. But the point for today is that the timing doesn't matter within the normal range. The environment matters. The interaction matters. The anxiety doesn't help.
And the word loss thing, I want to come back to that because it's the one that feels most alarming. A child says a word, you hear it, you celebrate, and then they stop. It feels like a loss. It feels like regression. But it's usually just the brain reorganizing. The word is still in there. It's just not the priority right now.
Like a file that gets moved to a different folder while you're working on something else.
That's not a bad analogy. The file is still on the disk. It's just not open right now. And it will come back, often with other words attached. The child who drops a word and then starts using it again a month later, that's not regression. That's consolidation.
So the advice to parents is, watch the trajectory, not the individual data points.
Yes. Look at the overall pattern. Is the child engaged? Are they communicating? Are they making progress in some domain? Are they responsive to interaction? If the answer is yes, the individual milestone dates are noise.
Let's talk about the reading question a bit more, because that's where the parental competition is most intense. The parent who brags about their four-year-old reading chapter books.
The four-year-old reading chapter books is usually the child of a parent who has been doing phonics drills since age two. And that child may indeed read early. But the question is whether that early reading produces any lasting advantage once the other kids learn to read. And the evidence says no. The kids who learn to read at five and six catch up. By third grade, the early readers are not distinguishable from the on-time readers, once you control for the environment.
So the early reading is a party trick, not a foundation.
It's a party trick with a lot of parental investment behind it. And the investment, the reading to the child, the talking about books, the exposure to language, that's the thing that matters. The early reading itself is just a symptom of that investment. It's not the active ingredient.
That's a useful reframe. The parent who is drilling phonics is doing something that looks productive but may not be. The parent who is reading to their child and talking about the story is doing something that looks ordinary but is actually the thing that matters.
And the drilling can be counterproductive. It can make reading a chore. It can make the child associate books with pressure. The child who is read to for pleasure learns that books are enjoyable. That's the foundation for later reading.
So the parental competition is not just pointless, it's potentially harmful. It pushes parents toward the drilling model and away from the pleasure model.
And it makes parents anxious. The parent who hears about the four-year-old reading chapter books goes home and looks at their four-year-old who is still sounding out three-letter words and thinks, I'm failing. When in fact, the four-year-old sounding out three-letter words is exactly where they should be.
There's a social media effect here too. The parents who post about their child's early milestones are the ones who have something to brag about. The parents whose children are developing on a normal schedule don't post. So the feed is full of early readers and early walkers, and the normal child looks like the exception.
That's selection bias. The visible cases are the extreme cases. The normal child is invisible. And that distorts the perception of what's normal.
So the parent scrolling through social media sees a world full of prodigies, and their own child looks ordinary by comparison. When in fact, the ordinary child is the norm, and the prodigies are the outliers.
And the prodigies are often not prodigies at all. They're just children whose parents are very invested in presenting them that way.
Let me pull us back to the science for a moment. The Jenni study, the Murray study, they both show washout within the normal range. Is there any domain where early achievement does predict later success?
Within the normal range, the evidence is thin. There are some studies that show early motor skills predict later physical activity levels, but the effect sizes are small. There are some studies that show early language skills predict later vocabulary, but again, small effects that wash out when you control for environment. The strongest predictors of later success are not milestone timing. They're the quality of the environment, the responsiveness of the caregiver, and the child's own executive function and social-emotional skills.
So the answer to Hannah's question is, no, doing something earlier within the normal range doesn't predict anything meaningful later in life. Early talkers don't become better communicators. Early walkers don't have any long-term advantage. Early readers don't become better students. The differences wash out.
That's the answer. And it's a liberating answer. It means the parent can stop worrying about the timeline and focus on the interaction. The thing that matters is the responsive, communicative environment. And Hannah is already providing that.
The obsession with milestones is essentially parental competition over things that don't matter much in the long run. That's Hannah's phrase, and it's accurate.
It is. And the competition is corrosive. It makes parents anxious. It makes them see their children as projects. It makes them miss the actual communication that's happening because they're waiting for the word count to hit some number.
There's a phrase I want to introduce, developmental cascades. The idea that small differences early on can compound over time, but in the case of milestones, the cascades don't work the way parents think. The cascade that matters is not the early walker getting a head start on exploration. It's the responsive caregiver building a secure attachment that supports all later development.
The cascade that matters is the interaction quality. The child who has a responsive caregiver learns that communication works, that their signals are understood, that they can influence their environment. That's the foundation for everything else. The timing of the first step is irrelevant compared to that.
So the parent who is worried about the timing of the first step is looking at the wrong thing. The thing to look at is the quality of the interaction. Is the child engaged? Are they communicating? Are they making progress in some domain? If the answer is yes, the timeline is irrelevant.
And the parent who is providing that responsive environment is doing the thing that matters, even if they're also anxious about the timeline. The anxiety is unnecessary, but the behavior it produces is often beneficial.
Except when the anxiety leads to drilling and pressure. That's the point where the anxiety stops being harmless and starts being counterproductive.
Yes. The parent who is reading to their child because they're anxious about language development is doing something good. The parent who is drilling their child on vocabulary because they're anxious is doing something that may backfire. The distinction is between providing a rich environment and demanding performance.
So the advice is, provide the environment, drop the performance anxiety.
That's the advice. And it's hard advice to follow, because the performance anxiety is baked into the culture. The milestones are everywhere. The charts, the apps, the social media posts, the well-meaning relatives who ask, is he walking yet? The whole culture is organized around the timeline.
Which is why Hannah's question is so important. She's asking whether the timeline matters, and the answer is no. The thing that matters is the interaction. And she's already doing that.
She is. And she's noticing the communication that's already there, the gestures, the facial expressions, the vocalizations. That's the responsive caregiver. She's seeing her child, not her child's milestone chart.
I think we've answered the question. But let me ask you one more thing. From the pediatrician side, what's the most common mistake parents make about milestones?
The most common mistake is comparing their child to another child. The neighbor's kid walked at ten months, so my kid should walk at ten months. But development is individual. The range is wide for a reason. The child who walks at fifteen months is not behind. They're just on a different schedule. And the schedule doesn't matter in the long run.
The parent who compares is setting themselves up for anxiety.
Yes. And the anxiety is unnecessary. The child who is developing typically, even at the late end of the normal range, is going to be fine. The milestones are screening tools, not predictors. They're there to catch the child who is outside the range entirely, not to rank the children who are inside it.
That's a good place to land. The milestones are a net, not a leaderboard.
A net, not a leaderboard.
Hilbert: Fisher-Price Smart Stages. Ninety-nine dollars. Two thousand one.
What?
Hilbert: The startup I worked for, BabyMetrics, we sold a smart baby monitor that claimed to predict future genius from early motor activity. The algorithm analyzed crawling patterns, grip strength, how many times a baby reached for a toy. It generated a developmental score. Parents got a weekly report with a percentile ranking. The pitch was, catch the genius early. The reality was, we were selling anxiety to parents who already had plenty.
I remember those. The early two thousands were full of that stuff.
Hilbert: The algorithm was pseudoscience. We had no longitudinal data. We had no validation. We had a marketing team and a database of normal milestone ranges from a nineteen seventies textbook. The whole thing was built on the assumption that earlier is better, which is exactly what you two just spent an hour dismantling.
You worked there.
Hilbert: Six months. I was the customer support lead. I read the emails from parents who were terrified because their baby scored in the fortieth percentile. Fortieth percentile. Perfectly normal. But the report made it sound like the child was falling behind. We got emails from parents who wanted to know what interventions they should do. Interventions. For a seven-month-old who scored slightly below average on grip strength.
What did you tell them?
Hilbert: I told them the truth, which was that the algorithm was garbage and the score didn't mean anything. My supervisor told me to stop telling them that. I left shortly after.
The company was selling exactly the anxiety we've been talking about.
Hilbert: The whole industry was. And it's still going. The apps are more sophisticated now, but the core product is the same. A score. A percentile. A reason to worry. The parents don't need it. The kids don't need it. But the company needs the parents to think they need it.
There's a historical angle here. The obsession with early milestones is partly a product of the twentieth century, the rise of developmental psychology as a parenting industry. The century of the child, they called it. Suddenly there were experts, and charts, and norms. And parents were told that they needed the experts to tell them if their child was okay.
Hilbert: My son walked at seventeen months. The algorithm would have flagged him as high-risk. He's twenty-eight now. He rock climbs. Perfectly coordinated. The algorithm didn't account for the fact that he was just a kid who didn't feel like walking until he felt like it.
Seventeen months is outside the normal range.
Hilbert: It's on the edge. His pediatrician said, he's fine, he's just lazy. He was right.
The pediatrician was looking at the whole child, not just the milestone. That's the difference.
Hilbert: The algorithm flagged me, too. I crawled in a non-standard pattern. I was thirty at the time. The algorithm didn't account for that. It just saw the crawling pattern and generated a score. High-risk non-walker. I was thirty years old and working at the company that made the thing.
The algorithm flagged you as a high-risk non-walker at thirty.
Hilbert: It was a demo. We were testing the motion sensors. I crawled across the office floor to see if the thing would register. It did. It gave me a developmental score in the second percentile. For a thirty-year-old man crawling on an office floor. The system didn't have an age field. It just assumed any crawling thing was a baby.
That's a perfect illustration of the problem. The system was measuring the behavior without any context. And the context is everything.
Hilbert: The context is the child. Is the child engaged? Are they communicating? Are they making progress? That's what matters. Not the percentile. Not the score. Not the date on the chart.
You agree with the washout idea.
Hilbert: I lived it. I sold the anxiety, and then I watched my own kid ignore the charts entirely. He walked when he wanted to. He talked when he wanted to. He's fine. The charts were wrong about him, and they were wrong about me.
The charts aren't wrong. They're just misused. They're screening tools. They're not meant to be used the way these companies use them.
Hilbert: That's the problem. The companies take a screening tool and turn it into a ranking system. And the ranking system creates anxiety. And the anxiety creates customers. It's a business model built on parental fear.
The fear is unnecessary. That's what the research shows.
Hilbert: The fear is the product. The milestones are just the packaging.
That's a grim way to put it, but it's accurate. The fear is the product.
Where does that leave us? If the timeline doesn't matter, why do we cling to it? Is it a need for control in the chaos of parenting?
I think it is. Parenting is radically uncertain. You don't know if you're doing it right. You don't know if your child will be okay. The milestones give you something to hold onto. But they're a false comfort. The thing that actually matters is the interaction, and that's not something you can chart.
Could we shift the focus from when to how? From the timing of achievements to the quality of interaction?
That's the shift I'd want to see. Not when did your child walk, but how do you respond when your child reaches for you. Not how many words does your child have, but how do you respond when your child points at something. That's the stuff that builds the foundation.
Daniel and Hannah's instinct to not worry about Ezra is backed by the science. The real predictor is the responsive, communicative environment they're providing.
It is. And the fact that Hannah is noticing Ezra's non-verbal communication, that she's seeing the gestures and the facial expressions and the climbing and the balance, that's the responsive caregiver. She's seeing her child, not her child's chart.
That's the thing to hold onto. The chart is a net. The interaction is the point.
This has been My Weird Prompts. Thanks to our producer, Hilbert Flumingtop. If you enjoyed this episode, leave us a review or email us at show at my weird prompts dot com. We'll be back soon.
See you tomorrow.
