Older, wiser, linguistically savvy: A comparative experimental study of grammatical evidentiality across younger and older generations in Turkish and Korean Speakers

Abstract

This study explores whether the ability to process grammatical evidentiality is compromised in older adults speaking Turkish and Korean, two languages that grammatically encode evidentiality. Building on previous research that suggests cognitive demands associated with language structures may reduce processing capacity in older adults, we conducted self-paced reading experiments using sentence contexts involving grammatical evidentials. We tested adult groups of young (N = 44, ages 19-27) and older (N = 37, ages 48-70) speakers of Korean and young (N = 31, ages 18-31) and older (N = 42, ages 50-85) speakers of Turkish. The results indicate that both language groups rated mismatched evidential verb forms as unacceptable, with Turkish speakers more likely to interpret mismatches as acceptable than Korean speakers. Notably, older Korean adults exhibited longer reading times (RTs) for direct evidential mismatches, while older Turkish adults showed longer RTs for indirect evidential verbs, suggesting age-related disruptions in processing. The findings only partially support the hypothesis that predicts grammatical processing differences in older compared to younger adults.