Language as tool: The analogy to primate cognition

In this paper, I explore the classic notion of 'language as tool' in connection with cultural tool practices in great apes. By showing that patterns of variation in ape tool use (e.g., nut-cracking) are identical to cross-linguistic patterns of variation in grammatical marking (e.g., the expression of reciprocity), I present new evidence for the cultural hypothesis of language. I argue that if both types of behavior are of cultural origin, the underlying cognitive abilities must likewise be the same. In this way, the linguistic notion of language as tool gains clear indicators of cultural development independently of language, and moreover a model of cognition and learning from primate research which so far has been marginalized in the study of language.