Human language is special because it is complex and allows us to share ideas, stories, and information in ways that no other animal can. But how do babies learn to speak? Scientists believe that a big part of this learning comes from infant-directed communication, the way adults talk directly to babies, often using a special tone or style that grabs their attention and helps them learn.
A recent study compared how much infant-directed vocal communication happens in humans and our closest relatives: the great apes (bonobos, chimpanzees, gorillas, and orangutans). The researchers wanted to know if talking directly to babies is something unique to humans or if it’s also common in other apes.
What Did the Study Find?
– Human infants receive much more direct communication than ape infants. When researchers observed both humans and apes, they found that the number of times adults spoke directly to human babies was hundreds of times higher than with ape infants.
– When looking at the proportion of all vocal activity that was directed at infants, about **95%** of human vocalizations around babies were directed at them. For apes, this number was less than 2%.
– Even when focusing only on mothers, human mothers spoke directly to their babies much more often than ape mothers did.
Why Does This Matter?
Infant-directed communication is important because it helps babies learn language. The special way adults talk to babies—using clearer sounds, higher pitch, and repetition—makes it easier for babies to pay attention and start understanding words. This kind of communication is found in many human cultures and is a key part of how language is passed from one generation to the next.
In contrast, nonhuman great apes rarely use direct vocal communication with their infants. Instead, ape infants mostly hear sounds and calls not meant specifically for them, called “surrounding communication.” This suggests that the way humans talk to babies may be a unique feature that helped our ancestors develop complex language.
