Previous research in evolutionary linguistics has made wide use of artificial language learning (ALL) paradigms, where learners are taught artificial languages in laboratory experiments and are subsequently tested in some way about the language they have learnt. The ALL framework has proved particularly useful in the study of the evolution of language, allowing the manipulation of specific linguistic phenomena that cannot be isolated for study in natural languages. Furthermore, this framework can test the output of individual participants, to uncover the cognitive biases of individual learners, but can also be implemented in a cultural evolutionary framework, investigating how participants acquire and change artificial languages in populations where they learn from and interact with each other. In this thesis, I present a novel methodology for studying the evolution of language in experimental populations. In the artificial sign language learning (ASLL) methodology I develop throughout this thesis, participants learn manual signalling systems that are used to interact with other participants. The ASLL methodology combines features of previous ALL methods as well as silent gesture, where hearing participants must communicate using only gesture and no speech. However, ASLL provides several advantages over previous methods. Firstly, reliance on the manual modality reduces the interference of participants’ native languages, exploiting a modality with linguistic potential that is not normally used linguistically by hearing language users. Secondly, research in the manual modality offers comparability with the only current evidence of language emergence and evolution in natural languages: emerging sign languages that have evolved over the last century. Although the silent gesture paradigm also makes use of the manual modality, it has thus far seen little implementation into a cultural evolutionary framework that allows closer modelling of natural languages that are subject to the processes of transmission to new learners and interaction between language users. The implementation and development of ASLL in the present work provides an experimental window onto the cultural evolution of language in the manual modality. I detail a set of experiments that manipulate both linguistic features (investigating category structure and verb constructions) and cultural context, to understand precisely how the processes of interaction and transmission shape language structure. The findings from these experiments offer a more precise understanding of the roles that different cultural mechanisms play in the evolution of language, and further builds a bridge between data collected from natural languages in the early stages of their evolution and the more constrained environments of experimental linguistic research.

This research study presents an investigation of interpreter trainees acquiring New Zealand Sign Language (NZSL) as a second language (L2) outside their formal classroom learning. This study was motivated firstly by a concern that a considerable reduction in learner and lecturer contact hours within an NZSL interpreting programme would compromise graduate NZSL competency, necessitating a compensatory approach predominantly in the context of the Deaf community. Secondly, the study attempts to address a marked gap in research related to L2 sign language learning from a socio-cultural perspective. Semi-structured interviews were conducted in a bilingual context (NZSL and English) in order to gain the ‘inside’ perspectives of six NZSL learners who had just completed a two-year Diploma in Sign Language Interpreting. The interviews sought to uncover the informal NZSL language learning opportunities used by the participants, especially within the social context of the Deaf community, and the individual learner strategies utilised by ‘good learners’ of NZSL. Interview data were transcribed and were analysed by employing qualitative methods. Coding of the data revealed a number of categories which were subsequently examined for salient themes relating to the research questions. The main findings of the study revolved around the significance of L2 learner access to social and material resources, especially within the Deaf socio-cultural context. Of particular significance was the enhancement of learner motivation and confidence as was the frequency and depth of interaction with Deaf people and degree of mediated NZSL learning from NZSL mentors. Of key importance were the social relationships and networks developed with L1 users, which facilitated access to an array of NZSL learning opportunities. Material language learning resources, such as NZSL video samples and equipment were also useful, when interaction with Deaf people was not possible due to heavy study demands, especially in the second year of the programme. Learner involvement in the Deaf community, particularly within Deaf social networks, resulted in significantly improved linguistic, pragmatic and socio-cultural competency. The findings of the study raise two main implications. Firstly, the study highlights the need for NZSL interpreting curriculum enrichment and the resourcing of the programme to foster learner autonomy. Secondly, to date there has been little research on adult L2 sign language learning outside the classroom context and the study may stimulate further studies of the acquisition of sign language as a second language. The study may also be of benefit to autonomous L2 sign language learners and stakeholders in sign language interpreting education around the world.

This research study presents an investigation of interpreter trainees acquiring New Zealand Sign Language (NZSL) as a second language (L2) outside their formal classroom learning. This study was motivated firstly by a concern that a considerable reduction in learner and lecturer contact hours within an NZSL interpreting programme would compromise graduate NZSL competency, necessitating a compensatory approach predominantly in the context of the Deaf community. Secondly, the study attempts to address a marked gap in research related to L2 sign language learning from a socio-cultural perspective. Semi-structured interviews were conducted in a bilingual context (NZSL and English) in order to gain the ‘inside’ perspectives of six NZSL learners who had just completed a two-year Diploma in Sign Language Interpreting. The interviews sought to uncover the informal NZSL language learning opportunities used by the participants, especially within the social context of the Deaf community, and the individual learner strategies utilised by ‘good learners’ of NZSL. Interview data were transcribed and were analysed by employing qualitative methods. Coding of the data revealed a number of categories which were subsequently examined for salient themes relating to the research questions. The main findings of the study revolved around the significance of L2 learner access to social and material resources, especially within the Deaf socio-cultural context. Of particular significance was the enhancement of learner motivation and confidence as was the frequency and depth of interaction with Deaf people and degree of mediated NZSL learning from NZSL mentors. Of key importance were the social relationships and networks developed with L1 users, which facilitated access to an array of NZSL learning opportunities. Material language learning resources, such as NZSL video samples and equipment were also useful, when interaction with Deaf people was not possible due to heavy study demands, especially in the second year of the programme. Learner involvement in the Deaf community, particularly within Deaf social networks, resulted in significantly improved linguistic, pragmatic and socio-cultural competency. The findings of the study raise two main implications. Firstly, the study highlights the need for NZSL interpreting curriculum enrichment and the resourcing of the programme to foster learner autonomy. Secondly, to date there has been little research on adult L2 sign language learning outside the classroom context and the study may stimulate further studies of the acquisition of sign language as a second language. The study may also be of benefit to autonomous L2 sign language learners and stakeholders in sign language interpreting education around the world.