Generics and typicality

Cimpian et al. (2010) observed that we accept generic statements of the form ‘Gs are f ’ on relatively weak evidence, but that if we are unfamiliar with group G and we learn a generic statement about it, we still interpret it in a much stronger way: (almost) all Gs are f . This paper makes use of notions like ‘representativeness’ and ‘contingency’ from (associative learning) psychology to provide a semantics of generics that explains why people accept generics based on weak evidence. We make use of the Heuristics and Biases approach of Tversky and Kahneman (1974) and the Associative Theory of Probability Judgements to explain pragmatically why people interpret generic statements in a much stronger way. The spirit of the approach has much in common with Leslie’s (2008) cognition-based ideas about generics, but the semantics is grounded on Cohen’s (1999) relative readings of generic sentences. The basic intuition is that a generic of the form ‘Gs are f ’ is true, not because most Gs are (or tend to have) f , but because f is typical for G, which means that f is valuably associated with G.