Beyond the implicit/explicit dichotomy: the pragmatics of plausible deniability

In everyday conversation, messages are often communicated indirectly, implicitly. Why do we seem to communicate so inefficiently? How speakers choose to express a message (modulating confidence, using less explicit formulations) has been proposed to impact how committed they will appear to be to its content. This commitment can be assessed in terms of accountability – is the speaker held accountable for what they communicated? – and deniability – can the speaker plausibly deny they intended to communicate it? We investigated two factors that may influence commitment to implicitly conveyed messages. In a preregistered online study, we tested the hypothesis that the degree of meaning strength (strongly or weakly communicated) and the level of meaning used by the speaker (an enrichment or a conversational implicature) modulate accountability and plausible deniability. Our results show that both meaning strength and level of meaning influence speaker accountability and plausible deniability. Participants perceived enrichments to be harder to deny than conversational implicatures, and strongly implied content as more difficult to deny than weakly implied content. Furthermore, participants held the speaker more accountable to content conveyed via an enrichment than to content conveyed via an implicature. These results corroborate previously found differences between levels of meaning (enrichment vs. implicature). They also highlight the largely understudied role of meaning strength as a cue to speaker commitment in communication.