Anna Jon-And, senior lecturer at Department of Romance Studies and Classics and researcher at the Centre for Cultural Evolution, Stockholm University

Human language is unique in its compositional and sequential form. Language evolution is often explained by advantages of communication. However, it has proven challenging to identify an evolutionary trajectory from a world without language to a world with language, especially while at the same time explaining why such an advantageous trait has not evolved in non-human animals (henceforth animals). Decoding sequential information is necessary for language, making sequence representation a tentative basic requirement for the evolution of language and other uniquely human phenomena. Here, we provide results from formal evolutionary analyses of the utility of sequence representation. Analyses show that sequence representation is exceedingly costly and that current memory systems found in animals may prevent abilities necessary for language to evolve. Furthermore, sequence representation may only evolve when sequential information is abundant and extensive learning opportunities are possible, two conditions likely fulfilled early in human evolution. These results provide a novel, logically plausible trajectory for the evolution of uniquely human cognition and language, and support the hypothesis that human culture is rooted in sequential processing abilities.