Where does language come from? The development of a naïve biological understanding of language.

We examined 3- to 10-year-old U.S. children's naïve biological beliefs about spoken language, probing developing beliefs about where language is located in the body. Experiment 1 (N = 128) introduced children to two aliens, each having eight parts: internal organs (brain and lungs), face parts (mouth and ears), limbs (arms and legs), and accessories (bag and hat). Participants were assigned to the Language condition (in which the aliens spoke two different languages) or the control Sports condition (in which the aliens played two different sports). We assessed children's reasoning about which parts were necessary to speak a language (or play a sport) by asking children to (a) create a new alien with the ability to speak a language (or play a sport) and (b) remove parts of an alien while preserving its ability to speak a language (or play a sport). In the Language condition, with age, children attributed language-speaking abilities to internal organs and face parts. In Experiment 2 (N = 32), a simplified language task revealed that 3- and 4-year-old children demonstrated a weaker, albeit present, biological belief about language. In Experiment 3 (N = 96), children decided at what point an alien would lose its ability to speak the language as the experimenter added or removed parts. Children attributed language-speaking abilities to specific internal organs and face parts (brain and mouth). We demonstrate that children believe that language is contained to specific parts of the body and that this "metabiological" reasoning increases with age.