syntax and semantics of laisser in causative constructions

The French verb laisser (‘to let’) allows for two different syntactic constructions, an Exceptional Case Marking (ECM) construction and a Faire-Infinitive (FI) construction with a postverbal Causee, and for two different interpretations, authorize and not-intervene. According to previous studies (e.g. Kayne 1975), constructions are related to interpretations: the ECM can express intentionality, the FI cannot. In this paper, we explore a different hypothesis: the ECM construction is underspecified and allows for both interpretations, while the FI is restricted to the not-intervening interpretation. We provide empirical evidence from three distinct forced choice tasks in which participants had to match constructions and interpretations. The results reveal that, contrary to both early observations and our initial hypothesis, both constructions may allow for both interpretations, and variation depends less on the syntactic configuration than on semantic and pragmatic factors, namely on the lexical inferences triggered by the embedded verb and the authority relation between Causer and Causee expressed in the contexts.