Humble Voices in Political Communication: A Speech Analysis Across Two Cultures

Classical works on affective and persuasive computing have pointed
out that technologies whose goal is to influence the user’s need to communicate
in a charismatic or dominant style, neglecting the potential persuasive strength
of other styles, such as a humble style. Humility can be defined as an epistemic
and interactional stance aimed at communicating the person’s attitude towards
an object, topic, or the interlocutor. Previous studies on persuasion in politics
conducted multimodal analyses to identify those postures, prosodic features,
gaze patterns, and facial expressions that convey humility. In this study, we
describe the features of humility associated with a speaker’s tone-of-voice, by
comparing two pairs of popular politicians from USA (Obama vs Trump) and
Italy (Gentiloni vs Salvini) during TV interviews. Results on the acoustic side
point out clear differences in the speech characteristics of humble vs. dominant
politicians: Gentiloni’s and Obama’s speech is characterized by short utterances,
more hesitations and disfluencies and fewer stressed words. The two speakers’
loudness levels are lower, and their voice qualities either more sonorant or even
breathier. We discuss our results with respect to their implications for persuasive
processes which can be associated not only to the speakers’ features but also to
the speaker-audience personality-trait matching.