Introduction. People often rely on subtle prosodic cues (e.g., changes in vocal pitch or tone) to infer a speaker's mental state. While much research has examined children's ability to identify emotions via prosody (e.g., anger, sadness), disbelief states have received little attention. Disbelief is especially important for development because, when justified, it can serve as a credibility cue to guide learning (e.g., disbelieving implausible information makes you a wise skeptic). Purpose. To determine what children understand about these mental state concepts and whether they can use vocal cues alone to detect them.
Methods & Results. Across two experiments, English-speaking children ages 6-8 years (Experiment 1 N = 56; Experiment 2 N = 60) were introduced to characters who differed in their disbelief toward implausible information (gullible believer vs. justified disbeliever). We tested whether (1) children can detect disbelief through prosodic cues, and (2) use a speaker's justified disbelief to guide their learning decisions and impressions of that speaker's credibility. Participants were randomly assigned to Control (explicit statements, e.g. "I believe that") versus Experimental conditions (prosodic cues only). We then asked questions examining children's ability to a) detect disbelief from prosody versus explicit statements and b) use that information to guide their impressions of the speaker's credibility (e.g., "Who's smarter?" "Who would be the most help with your homework?"). Results suggest that children this age understand that justified disbelief can signal credibility. However, their ability to detect justified disbelief using prosodic cues alone may be tenuous, especially earlier in development.
Conclusions. Children are remarkably savvy learners and use even subtle cues to determine the credibility of others. These results are discussed in terms of their implications for social cognition, the development of critical thinking, and the practical applications for information consumption and education.
