In a January 2017 study published in the journal Proceedings of Royal Society B, researchers sought to answer a couple of pet owners' burning questions: Why do we use "dog-directed speech" (translation: baby talk), and do dogs pay attention to it? As it turns out, the study found that dog-directed speech is much like infant-directed speech — puppies and babies responded similarly to high-pitched voices. As the study notes, "adult women show similar brain activation patterns" when presented with a picture of their dog and a picture of their own children. It might have something to do with our love of baby schema, or infantile physical features.

With this in mind, the researchers had 30 female subjects view photos of dogs and say common phrases like "Who's a good boy?" The volunteers then read the same phrases of praise to an adult human. Unsurprisingly, the women used baby talk when looking at the puppy images and a normal voice when speaking to the human. Next, the researchers played their baby talk recordings to dogs of varying ages. As expected, the puppies showed a strong response; they "barked and ran toward the loudspeaker, crouching down in a pose used to start a round of horseplay," as Smithsonian explains. When the researchers played the women's normal voice, the puppies didn't give nearly the same response. But here's the kicker: The adult dogs couldn't care less. One glance at the speaker — that's all, folks.

Why don't adult dogs care about your cutesy voice? As bioacoustician and co-author of the study Nicolas Mathevon explained to Smithsonian, older dogs might just be more choosy. Instead of reacting to strangers' voices, "they want only to react with a familiar person." So it's not that they don't like people as much as puppies do; they just prefer a familiar voice to that of a random volunteer.

The study concludes with two takeaways: only puppies are "highly responsive" to your baby talk, and the pitch of your voice is important in "driving puppy behavioral response." While the researchers aren't sure of the significance (if any) of these findings yet, they note in the study that pet owners use baby talk for all dogs, no matter their age. This is a "spontaneous attempt to get the attention of non-verbal, rather than just juvenile listeners." Babies are nonverbal, and dogs are nonverbal with infantile traits, so why not use baby talk for both? After all, your dog is still a good boy.

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Find out just how long dogs have been man's best friend in "Our Dogs, Ourselves: The Story of a Singular Bond" by Alexandra Horowitz. The audiobook is free with an Audible trial. We handpick reading recommendations we think you may like. If you choose to make a purchase, Curiosity will get a share of the sale.