Mentalising is assumed to be involved in decision-making that is necessary to social interaction. We investigated the relationship between mentalising and three types of strategic games - Prisoners' Dilemma, Dictator and Ultimatum - in children with and without autistic spectrum disorders. Overall, the results revealed less dramatic differences than expected among the normally developing age groups and the children with autism, suggesting that in these laboratory tasks, mentalising skills are not always necessary. There were, nonetheless, some important findings. Young children were more cautious about initiating cooperation than their older peers and, in bargaining situations, they were less generous in their opening unilateral grants and over-solicitous of an empowered receiver. Participants with autism did have a harder time shifting strategy between versions of the Prisoners' Dilemma, and they were much more likely to accept low initial offers in the Ultimatum game and to refuse fair proposals. In addition, participants' measured mentalising abilities explain intentional and strategic behaviour within the prisoners' dilemma and the avoidance of unsuccessful ultimatum proposals
