This twin study examined the genetic and environmental etiology of vocabulary, syntax, and their association in first graders. French-speaking same-sex twins (n = 555) completed two vocabulary tests, and two scores of syntax were calculated from their spontaneous speech at 7 years of age. Multivariate latent factor genetic analyses showed that…

Three experiments investigated the acquisition of English epistemic modal verbs (e.g., "may", "have to"). Semantically, these verbs encode possibility or necessity with respect to available evidence. Pragmatically, the use of weak epistemic modals often gives rise to scalar conversational inferences (e.g., "The toy may be…

The aim of the current study was to examine different aspects of procedural memory in young adults who varied with regard to their language abilities. We selected a sample of procedural memory tasks, each of which represented a unique type of procedural learning, and has been linked, at least partially, to the functionality of the corticostriatal…