The question of how language emerged concerns itself with both the biological evolution of the various cognitive capacities deemed necessary for language and the cultural evolution of languages, beginning from theorized proto-languages. It should be noted that cultural evolution should not be considered in isolation from its biological counterpart, as the cognitive adaptations an individual is equipped with bear implications for social interaction and learning.
Upon establishment, a language requires to be learned by subsequent generations, each from a prior generation, in a cross-generational manner, also known as vertical cultural transmission.
People learn a language from other people who once learned that language themselves.
Studies on cultural transmission seek to explain the changes an emergent language system undergoes.
The cultural transmission of a language can be said to give rise to design without intention and designer.
Exposure to linguistic behavior exhibited by members of one’s speech community induces one’s production of particular language properties. The resulting language used by one in turn translates to observable linguistic behavior which shapes the language of further members. Cultural evolution of the language is thus enabled by this cycle of repeated induction and elicitation of linguistic behavior.
Simulations of cultural transmission are based on the belief that when language is culturally transmitted, it develops:
- Structure
- Key design features unique to language over other communication systems
- Enhanced learnability through minimization of errors
The models of reserach include computational agent-based simulations, mathematical models, and most recently, laboratory experiments.
Pioneer work on agent-based simulations sought to explain how negotiation due to learners’ biases and interaction between them influence communication systems greatly. Subsequent studies focused largely on the development of linguistic structure as a byproduct of cultural learning (specifically iterated learning), despite poverty of the stimulus. Work on mathematical models followed, supplementing the findings of such agent-based simulations through mathematical characterizations of changes effected by cultural transmission.
To support prior computational and mathematical models empirically, laboratory experiments aim to demonstrate how cumulative, adaptive, and non-intentional the cultural evolution of language is, by using human participants.
2.2.1 Challenges
One significant challenge faced by studies on cultural evolution remains to be the arguably reductionist approach taken. Any given language is constituted by thousands of language systems (capturing pragmatic, semantic, morphological, and phonological distinctions) and language strategies, of which all are intertwined. No model can hope to closely replicate all aspects of language evolution through simulation.
Despite availability of real-life observations of cultural transmission with the likes of Nicaraguan Sign Language, study of genuine emergence remains limited by the lack of direct, natural, data. Hence, only indirect evidence can be drawn.