Elcos are common, ajajatas are weird: Manner implicatures guide the interpretation of unfamiliar words for French children and for adults in 18 languages.
Overly long or effortful utterances are interpreted as carrying more information than short or easy ones-a phenomenon known as manner implicatures in pragmatics. Can this mechanism guide the interpretation of unfamiliar words? In seven studies testing adults (N = 1,762) and children (N = 282), participants had to pair two words in an unknown language (e.g., "elco" and "ajajata") with two referents, one more prototypical than the other (e.g., a green crocodile and a yellow crocodile). The less prototypical referent is less expected and more surprising; thus, the action of referring to it carries more information than the action of referring to the more prototypical referent. We predicted that shorter words would be preferentially paired with prototypical referents. This effect was verified on adult participants inside and across 18 languages and held even when participants explicitly claimed to have used no strategy at all. Varying the respective prototypicality of the stimuli did not measurably change this effect: Adult participants responded similarly to a large differential in prototypicality as to a more moderate one. French children aged 3 to 11 also showed the predicted effect, with little discernible effect of age. Consistent with manner implicatures, adult participants (across four languages) and French children also show the predicted effect when the phonotactic complexity of words is manipulated instead of their length. Thus, manner implicatures guide the interpretation of unfamiliar words by children and adults. These results are consistent with the view that costlier messages are generally interpreted as carrying more information. (PsycInfo Database Record (c) 2026 APA, all rights reserved).