Exploring the Relationship Between Mental Boundary Strength and Phonetic Accommodation

We motivate a possible relationship between the psychological concept of mental boundaries and the linguistic phenomenon of phonetic accommodation, proposing that thinner boundaries may indicate a greater disposition to phonetically adapt to an interlocutor. To enable research on this relationship with German speakers, we translated the English short version of the Boundary Questionnaire (BQ-Sh), an established instrument for measuring the strength of mental boundaries, and demonstrated that the resulting German adaptation (BQ-Sh-G) can be used equivalently to the BQ-Sh. As the Big Five personality traits have previously been considered in research on both mental boundaries and phonetic accommodation, we explored the relationship between the BQ-Sh-G and the NEO-Five Factor Inventory. Consistent with previous literature, the BQ-Sh-G score correlated positively with Neuroticism and Openness, as well as negatively with Conscientiousness. We collected BQ-Sh-G scores from participants of an experiment on phonetic accommodation in a human-computer interaction context, specifically investigating the realization of the word ending 〈-ig〉 and the intonation of wh-questions in German. The analysis revealed a tendency for thicker mental boundaries to correspond with more convergence to 〈-ig〉 variants. Taking into account the results of previous work exploring the influence of the Big Five on the same data, we conclude that speakers may accommodate to different types of phonetic features depending on different personality traits. We encourage future work to investigate this further, while also exploring the predictive potential of the boundary construct with respect to a general disposition to phonetic accommodation, that is, examining a large number of phonetic features simultaneously.