Previous research has identified contradictory patterns in autism upon probabilistic reasoning tasks, and high levels of self-report paranoia symptoms have also been reported. To explore this relationship, the present study assessed 64 non-autistic and 39 autistic adults on two variants of a probabilistic reasoning task which examined the amount of evidence required before making a decision and 'jumping to conclusions' (a neutral beads task and an emotionally-salient words variant). The autism group was found to require significantly more evidence before making a decision and to have significantly less jumping to conclusions than the non-autistic group. For those with relatively low levels of paranoia, the emotionally-salient variant impacted on the non-autistic group, but not the autism group.