You’ve probably noticed how adults often talk differently to babies than to other adults or even toddlers. They raise the pitch of their voices and do other things we would consider inappropriate or insulting in normal adult conversation. A few even have their voices take on a saccharine quality guaranteed to nauseate any nonparent (and even some parents) in the room.

We generally refer to this shift in tone, syntax, and attitude as “baby talk.” It’s something that we expect in that particular interaction, so much so that an adult who approaches a newborn with serious demeanor and says, “It’s good to see you again, Robert. How was your day?” would be regarded as insensitive to children, or worse! Yet those words have no less meaning to the baby than a more socially acceptable statement like, “Oh, what a cute little tummy you have!”

I remember one time when my son Michael, then eighteen months old and sitting in his stroller, and I were going to get some food from a local market. My son was very sociable and outgoing. He’d learned quickly that if he said, “Hi!” to an adult he was likely to get a response and some extra attention. As we walked to the store he would cry out a greeting to every passerby, each of whom answered him and made a comment like, “Oh, aren’t you cute.” Needless to say, he basked in the limelight of this extra attention.

As we approached the market he spied a woman in a business suit coming toward us, “Hi!” he cried. But she had her noes buried in a report of some sort while she walked. “Hi!” he yelled once more, only louder. Again she gave no response. Finally, he waited until she was only two feet ahead of his stroller and bellowed, “HI!!!”

The woman stopped dead in her tracks, looked at him with surprise and muttered, “Oh, um, hello. I mean, good evening. Sorry, but I have to go.” It was hysterically funny, not because anything she said was outlandish or inappropriate, especially if she had been talking to another adult. What made it funny, and what probably made her stumble over her words as well, was that she was unable to mentally switch gears to how she was expected to talk to a young child.

What’s going on when we engage in baby talk is more than “cute” or “simple” speech. There’s a clear but complex pattern that includes not only a higher-than-normal pitch, but a greater range of tones which reinforce the emotional content of the message. We also drag out certain words for emphasis, such as, “Oh, you’re such a g-o-o-d girl! You finished your w-h-o-l-e bottle.” We also tend to speak more slowly, with simpler grammar and with clearer enunciation, much as we might when talking to an adult who isn’t fluent in our language.

Parents of babies and even toddlers often verbalize both sides of their conversation, either implicitly or explicitly. “Would you like some mashed banana? Oh, you would. Well, I’ll get you some.” We may be inordinately descriptive, assigning names to objects, emotions, and status, often doing so with a good deal of repetition. “That’s your teddy bear, Chrissie. He’s a big teddy bear, a brown teddy bear.” “My, you sound cranky today! Didn’t you get enough sleep?” or “Let me put on your diaper. First this side. Then the other side. Now it’s a-l-l done.”

There appear to be clear reasons for and benefits from these utterances. A higher-pitched voice seems more attractive to babies. Slowing down the speed, simplifying grammar and syntax, naming objects and emotions, describing status, and modeling conversations all make it easier for a child to puzzle through what language is all about.

Similarly, using a child’s name instead of a pronoun (“That’s Debbie’s rattle” instead of “That’s your rattle”) probably helps a child understand her name. But one of the most surprising aspects of baby talk is the way we use diminutives and other special words with babies that we don’t use with adults. For example, when my son was very young I found myself saying “doggie” and “puppy” to him instead of “dog,” and referring to our two cats as “kitties.” If anything, doggie, puppy and kitty are more complex words than dog and cat. Several times I caught myself referring to one of our cats, who was named Zabar, after one of my favorite stores in Manhattan, as “Zabar-kitty” — which is both conceptually and phonetically much more complex than necessary.

I’ve heard many parents do the same thing, substituting “tummy” for “stomach” or saying “choo-choo train” instead of simply “train,” for example. We’d never expect an adult to complain of a tummyache or a commuter to talk about taking the 8:05 choo-choo train. Why do we use words like that with children? By using more complex words, it’s almost as if we want to make language more difficult for them to acquire.

One compelling theory is that we talk to babies this way not so much for their sake, but for our own. By shifting our patterns of speech we are acknowledging our special relationship with babies. The real purpose (and benefit) of baby talk is to bolster the social interaction between parent and child. Shifting our style of speech forces us to pay more attention to what we say and, therefore, to the person we’re talking to. The topic and details of the conversation don’t matter much. It’s the emotions and the extra attention that convey the most important message — to both generations.