A diminished propensity to compute scalar implicatures is linked to autistic traits

We investigated whether there is an association between autistic traits in the broader phenotype and the ability to compute scalar implicatures. Previous studies found that the frequency of autistic traits is higher in students of science than of humanities. Here we recorded the frequency of rejection of underinformative scalar items in students enrolled either in a science or in a humanities curriculum and assessed their autistic traits using the Autism-Spectrum Quotient questionnaire. We found that rejections were less frequent in science curricula students than in humanities curricula students. Moreover, rejections were associated negatively with autistic traits and positively with performance on Theory-of-Mind tasks. These findings suggest that autism cognitive phenotype is negatively associated with a propensity to spontaneously derive scalar implicatures.