Abstract
Children's language development is tied to their linguistic input. While most of this research has focused on adult speech, around the world, children regularly engage with other children, in the home or in early childhood education settings. Here, I contextualize the frequency of interactions with other children. I then highlight properties of speech from children, such as acoustic signature and content, which might make other children's speech particularly relevant for language learning. Finally, I discuss how considering speech from children allows scholars to create theories that include societies around the world, where caretaking often involves more children and higher birthrates are common. I conclude that theories of language development should consider speech from other children as an important component.