The Language and Cognition group maintains about a dozen field sites around the world (listed below), where languages are described often for the first time. The research involves language description from the ground up: developing a writing system, producing grammars and dictionaries, and the collection of video- and audiotape so that it can be transcribed and annotated as a permanent record in the institute's archives.

Expertise is also maintained in the following languages, both within the group and through external collaboration:

American Sign Language, Biak, British Sign Language, Cantonese, Dutch, English, Ewe, Farsi, French, German, Hindi, Hungarian, Jalonke, Japanese, Kalasha, Kuuk Thaayorre, Lavukaleve, Likpe, Lowland Chontal, Malay, Mandarin, Menggwa Dla, Mian, Miraña, Moroccan Arabic, Otomi, Polish, Punjabi, Romansch, Savosavo, Slovak, Spanish, Sranan, Swedish, Tamil, Tidore, Tiriyó, Touo, Turkish, Yoruba.