Why unrelated languages share the same words for parents

HostIt's one of those things we just take for granted. You go anywhere on the map, and whether someone is speaking English or Swahili or Mandarin, the words for mother and father sound almost identical. It feels like there has to be some kind of ancient, shared history there, like we're all part of one giant family tree that never forgot its first words. But is that actually why a baby in Tokyo and a baby in London both say mama?

GuestIt's a beautiful thought, but the real story is actually a lot more about how a baby is built than where their ancestors came from. To understand it, you have to look at a nursing infant. Their bodies are set up in a very specific way. A newborn has a really large tongue compared to the size of their mouth, and their voice box, or larynx, sits much higher in the throat than yours or mine. That high position is actually a survival trick. It lets them breathe and swallow at the same time without choking. But it also means they don't have a lot of control over making complex sounds. When a baby is feeding or just waiting for food, their lips are naturally sealed. If they start to hum or vibrate their vocal cords in that position, the air has to go through the nose. That produces a nasal murmur. It's the easiest sound a human being can possibly make. It's basically just a hum with the mouth shut, which is exactly how you get that mmm sound.

HostWait, so you're saying it's not even a word? If I'm a parent and I hear my baby say mama for the first time, you're telling me they're just making a random noise because they're hungry? That feels a bit cold.

GuestWell, it's not that the sound is meaningless, but it might not mean what we think it means. There was a famous linguist who looked into this, and he argued that mama isn't a word the child learns from the parent. It's actually a sound the parent claims for themselves. Think about the situation. The baby is making these easy lip sounds, like m or p or b, mostly just out of comfort or anticipation while they eat. But the parents are standing there, hovering, just waiting for that first sign of a connection. When the baby goes ma-ma, the mother hears her own name. She gets excited, she smiles, she picks the baby up. That creates this huge social reward. We basically hijack the simplest noise a baby can physically make and we say, oh, that's me. You're talking to me. Over time, that feedback loop turns a random feeding noise into a real name that stays in the language forever.

HostI don't know, it still feels like a bit of a leap. Even if we admit that mama is just a hum, what about papa or baba? Those don't sound like a hum at all. They're much sharper. Why would those sounds be so common too if they're not part of that same feeding noise?

GuestThat comes down to the next step in how a baby's physical skills grow. After they master that simple nasal hum, they start to get better at controlling the air in their mouth. The next easiest thing for them to do is what we call a stop. This is where you build up a little bit of air pressure behind your lips or your tongue and then just let it go all at once. That's how you get a p or a b or a t sound. It's a big jump in skill. You're moving from a passive sound like m, which just flows out of the nose, to an active release of breath. This is why we almost always see a split. The m sound, the most primitive one, usually goes to the primary caregiver. Then the papa or tata sound follows as a second name because it represents the baby moving into a slightly more advanced stage of being able to work their mouth and breath.

HostBut it's so universal. I still struggle with the idea that every culture just happened to pick the same sounds by accident. It seems way more likely that there was one original mother tongue way back in history, and we all just kept those two words while everything else changed.

GuestPeople have looked for that one original language for a long time, but the evidence points somewhere else. We call it convergent evolution. It's the same reason birds and bats both have wings even though they're not closely related. They both just faced the same problem and hit on the same solution. Human babies are the same way. No matter where a child is born, they have the same high voice box, the same big tongue, and the same physical limits. They all invent the same sounds at the same stages of their life because their bodies are identical. Even in places where the words seem different, you can see the pattern. In very old Japanese, the word for mother was actually closer to a p sound, but it still comes from that same small pool of sounds that a child can master before they even have teeth. It's not history that connects these words. It's the physical reality of being a human infant.

HostThat nursing baby humming with their mouth full basically wrote the first page of every dictionary on earth without even knowing it.

GuestThe anatomy of a hungry infant is what really built the foundation for how we talk to the people we love the most.

HostThose first sounds we make aren't just a way to get fed, they're the start of a loop that turns a physical reflex into the very first bond we ever name.