“Experts think…” The production and comprehension of propositional attitude generics

Propositional attitude generics such as “Experts think early humans ate grass” report an epistemic state (e.g., think, believe, say) that is generalised to a wider community (e.g., Experts, Scientists, Academics). These generics are often used in place of quantified claims (e.g., “Some experts think…”) but three pre-registered experiments (N = 4891) indicate that this lexical choice risks misrepresenting the true degree of scientific consensus. Relative to “Some experts think…” the generic “Experts think…” was more likely to be understood as “All Experts” or “Possibly all Experts” and less likely to invite the scalar inference “Not all Experts”. Consistent with this, the choice to use generic language became increasingly likely as expert consensus approached unanimity. Propositional attitude generics can imply a high degree of consensus and keep open the possibility of universal agreement. To avoid overgeneralization, they should be used with caution where the objective degree of consensus is unknown.