The role of prosody in interpreting causality in English discourse

Previous studies have well established that certain causal connectives encode information about the semantic-pragmatic distinction between different types of causal relations such as CAUSE-CONSEQUENCE versus CLAIM-ARGUMENT relations. These "specialized" causal connectives assist listeners in discerning different types of causality. Additionally, research has demonstrated that utterances expressing CLAIM-ARGUMENT relations exhibit distinct prosodic characteristics compared to utterances expressing CAUSE-CONSEQUENCE relations. However, it remains unknown whether the prosodic characteristics of utterances expressing causality can aid listeners in determining the specific type of causality being conveyed. To address this knowledge gap, this study investigates the impact of the prosody, specifically the prosody of the causal connective so in English, on listeners' interpretation of the type of causality expressed. We conducted a perception experiment employing a forced-choice discourse completion task, where the participants were required to select a continuation for each sound clip they heard. The sound clip consisted of factual events followed by the causal connective so. We found that the odds of listeners choosing subjective continuations over objective continuations increased when the connective so at the end of the sound clip was pronounced with subjective causality prosodic features, such as prolonged duration and a concave f0 contour. This finding suggests that the prosody of the connective so plays a role in conveying subjectivity in causality, guiding listeners in interpreting causal relations. In addition, it is important to note that our data revealed individual variation among listeners in their interpretations of prosodic information related to subjective-objective causality contrast.