Every Baby Laugh is a Eureka!

There is a lot of work on child development. Some of it is dry analysis. The vast majority is on how we can mold children into a desired image—how to teach them, shape them, optimize them. But I think there is something missing. We spend so much time studying what we can teach babies that we've forgotten to ask: What can babies teach us?

I have listened to when babies laugh. I could be wrong, but it seems that babies laugh when they learn.

Not after they learn. Not because learning is over and they're relieved. But in the moment of understanding itself—that split second when a pattern clicks into place, when prediction meets confirmation, when the world suddenly makes a new kind of sense.

Every laugh is a tiny "Eureka!"

And if that's true, babies are having more profound insights per day than Einstein had in his adult lifetime. Because for them, everything is still surprising and pattern-able: "Oh! Gravity is consistent!" "Wait—faces have a structure!" "Things that leave can return!" "My hand belongs to me!"

This isn't just cute. It's epistemology in real-time.

The Game That Teaches Everything

Consider peekaboo. The standard explanation goes like this: babies laugh at peekaboo because they're learning "object permanence"—the understanding that things continue to exist even when you can't see them. Jean Piaget identified this as a key developmental milestone demonstrated around 8 months.

This is demonstrated in this short.

But this explanation feels insufficient.

What if peekaboo is actually teaching something more fundamental? Perhaps related to trust and return is learning that memory itself can be trusted.

Think about it: The face disappears from perception but remains in memory. Then perception confirms what memory held. This is the baby's first empirical verification of internal cognitive apparatus. Baby's first epistemological experiment.

Peekaboo isn't just teaching "mom still exists when I can't see her." It's teaching:

• My internal representations correspond to external reality
• There is a "before" and "after" that connect
• Prediction works
• The world is consistent enough to be knowable
• I persist as the observer of all this

And the companion's role? By reliably returning, the companion becomes the guarantor of a trustworthy universe. The companion is not just teaching object permanence—but teaching that reality itself can be trusted, that memory is reliable, that the future resembles the past enough to be worth predicting.

The joy in peekaboo might be the baby's celebration of this discovery: "My mind works! The world is knowable! I can trust my own experience!"

However, be aware. The peekaboo procedure is often overused and is better replaced with a careful corpus of tests. This baby explains it all.

This reframes what happens when caregiving is inconsistent or neglectful. It's not just about attachment—it's about undermining babies' ability to trust the most fundamental tool they have: their own perception and memory. A caregiver who sometimes returns and sometimes doesn't teaches that reality is arbitrary, that memory is unreliable, that prediction is futile.

The Phenomenology of Understanding

Charles Darwin as well as Jean Piaget observed their own children and concluded that smiles and playfulness were signs of cognitive mastery. More recently, developmental psychologist Caspar Addyman at Global Parenting Initiative has dedicated his career to studying baby laughter. His observation: babies "seem like they're being made happy when they get something new."

Incongruity

Research confirms what any attentive parent notices: babies laugh at incongruity—but specifically, resolved incongruity. Around 6-8 months, infants will laugh at Dad putting a cloth in his mouth or Mom putting a book on her head. They're laughing at the violation of what they've just learned about how objects are typically used—which means they had to have learned the pattern first. Dr. Addyman has blue hair and I wonder how babies respond to him the first time they see him.

What are the best procedures for testing this?

Neuroscience

Neuroscience research confirms this: laughter activates the brain's reward system, releasing dopamine, which enhances learning and memory. When babies laugh, they're not just having fun—they're consolidating new understanding, reinforcing the neural pathways that just fired successfully.

That is, it goes both ways.

Babies seek learning instances

But there's a social dimension too. Addyman theorizes that babies laugh to reward other people for staying engaged in the learning game. Their delight drives adults to continue helping them. It's a brilliant strategy: the giggle ensures the partnership continues, that the guiding companion, perhaps a parent, stays invested in helping the baby master the next thing.

Bundle it up

So baby laughter is simultaneously:

1. An expression of "I got it!"—the joy of successful pattern recognition
2. A reinforcement mechanism—dopamine reward that consolidates learning
3. A social signal—"Keep doing that! This is the right level of challenge!"
4. An invitation to continue—ensuring the companion remains engaged

If joy is the phenomenological signature of understanding, then babies are constantly announcing their epistemic victories. We're not teaching so much as we're witnesses to discovery.

What We Get Wrong About Common Ground

Now here's the leap: I think understanding this is part of the foundation for fruitful dialogue. In finding common ground, we might look to what is common in our models of the world.

We systematically misidentify where common ground actually lies.

We think it's in:

• Shared conclusions (political positions, religious beliefs, moral judgments)
• Shared identities (nationality, profession, generation)
• Shared language and culture

But babies suggest it's actually in:

• Shared perceptual architecture (we all live in bodies that process reality similarly)
• Shared learning mechanisms (we all build models through pattern-recognition)
• Shared emotional responses to understanding (cognition feels like something—and what it feels like is delight)
• Shared experiences of existence (gravity, causation, persistence, memory, time)

Before they can speak, babies are already doing something remarkable: modeling another mind's model of the world. Developmental psychologists call this "shared intentionality"—Michael Tomasello's term for the uniquely human capacity to understand that others have goals and mental states. Research shows that babies as young as 14 months can perceive the unfulfilled goals of others and intervene to help them. They're demonstrating "shared intentionality"—understanding that others have minds, goals, and models of reality.

They're laughing when they discover shared patterns. They show more delight when adults respond, when there's mutual recognition, joint attention. This is dialogue before language: recognizing that another mind is running similar processes on similar inputs.

The Architecture of Misunderstanding

Here's what happens in most failed dialogues:

We enter trying to find agreement on conclusions—the most elaborated, personal, culturally-constructed parts of our world-models. The parts LEAST likely to overlap.

Meanwhile, we ignore the foundations—the parts MOST likely to overlap—because they seem "too basic" or "not relevant" to whatever we're arguing about.

It's like trying to build a bridge from the top down.

When we look for common ground in conclusions and fail to find it, we make a devastating error: We conclude the other person is fundamentally alien.

"They don't share my values" becomes "They don't share my humanity." "They don't see what's obvious" becomes "They don't see reality." "They won't agree with me" becomes "They can't be reasoned with."

But if we understood where common ground actually lies, we'd realize:

• They DO share your humanity features (same foundational model)
• They DO see reality (through the same perceptual apparatus)
• They CAN be reasoned with (using the same inference mechanisms)

They just built a different superstructure on the same foundation. And that's not alien—that's exactly what humans do. We all start with object permanence, causation, pattern-recognition, theory of mind. Then we build elaborate, divergent structures on top of these shared foundations based on different evidence, different experiences, different cultural contexts.

The question isn't "Why don't you see what I see?" (which assumes alien-ness).

The question is "With our common foundation, how did you build that?" (which assumes sharing attributes common among humans and honoring curiosity.)

The practice: Dialogue on top of development

So here's the principle: Build dialogue the same way babies build understanding.

We should dialogue the way babies learn—from foundations upward, with joy at each layer of shared pattern discovered.

In practice, this means:

1. Start below language. Before debating positions, establish shared experience. "We're both sitting here. We both want this conversation to be productive rather than painful. We both prefer understanding to confusion." 👂

2. Work from embodiment. "We both get hungry. We both know what it's like to be surprised. We both recognize faces and read emotion. We both feel satisfaction when things make sense." 👂

3. Acknowledge shared developmental history. "We both had to learn object permanence. We both trusted adults to return. We both built predictive models. We both experienced that 'Eureka!' feeling when something clicked." 👂

4. Recognize shared epistemology. "We both build models through pattern-recognition. We both adjust beliefs based on evidence. We both feel dissonance when our predictions fail. We both seek coherence. We both listen." ⤴️

5. Only then move upward. Once you've established foundation, you can explore: "Where did our models diverge? What different patterns did we notice? What different evidence shaped your conclusions?" ❓

6. Stay playful. Maintain the baby's experimental attitude—"Let's see what happens when..." rather than "You must accept..." 👅

7. Welcome surprise. Babies laughs at violation of expectation because it means they learned something. Be willing to have your model updated. That should feel good—like a laugh, a tiny "Eureka!" 😮

What This Changes

When you expect common ground in conclusions, you're constantly disappointed and alienated.

When you expect common ground in foundations, you're constantly discovering connection—even with people who draw opposite conclusions.

This changes the emotional tenor entirely:

From: "Why can't you see what I see?" (frustration at alien-ness)
To: "How did you build that from our shared foundation?" (curiosity about divergent paths)

From: Debate (defending positions from attack)
To: Collaborative epistemology (tracing how we each built our models)

From: Winning or losing
To: Mutual discovery (even if we still disagree at the end)

Perhaps genuine dialogue requires recovering something like the baby's laugh—a signal of successful pattern-matching. Not agreement (which can be coerced), but genuine recognition: "Oh! I see what you're seeing!" That moment when you understand someone's position even if you don't accept it—that should feel like understanding anything: a small joy, a "Eureka!"

Laughter is difficult to fake, researchers note, and it creates trust and community. Maybe the most profound dialogues aren't debates but rather collaborative explorations—two people discovering together what patterns they share and where they diverge, with something like a baby's delight at each new understanding.

The Deeper Promise

If common ground lies in how we learn rather than what we've learned, then:

• No one is irredeemably "other"—we all share the same cognitive architecture
• Understanding is always possible—even without agreement
• Dialogue can be joyful—each recognition is a small "Eureka!"
• Difference becomes interesting rather than threatening—divergent paths from shared origins

Philosopher Gareth Matthews spent his career demonstrating that children ages 3-7 naturally engage in genuinely philosophical thought, asking questions about existence, knowledge, and ethics that philosophers have grappled with for millennia. But he noticed these questions tend to disappear around age 8 or 9, when children become "well socialized in school."

We train it out of them. We replace the intrinsic joy of understanding with extrinsic rewards. We teach that learning is work rather than play, duty rather than delight.

Babies still know what we've forgotten: understanding is inherently pleasurable. The laughing proves it.

Maybe what babies teach us most fundamentally is this: the capacity for joy and the capacity for understanding are the same capacity. Cognition isn't separate from emotion—it feels like something. And what successful cognition feels like is delight.

In dialogue, we could recover this. Not the false joy of "winning" or the grim satisfaction of "being right," but the genuine delight of mutual comprehension—the moment when two minds recognize they're running similar patterns on similar data, even if they've built different conclusions.

That moment of recognition—"I see what you see, even though I see it differently"—might be the closest adults get to the baby's laugh.

And it might be exactly what we need.

I invite you to try this: In your next difficult conversation, don't look for agreement. Look for the foundations you share. Start with "we both..." and build upward. Notice what happens.

And if you find yourself understanding—really understanding—someone you disagree with? Pay attention to how it feels. Perhaps it feels a baby's laugh. A tiny "Eureka!"