"What is fair for you?" judgments and decisions about fairness and theory of mind.

Theory of Mind (ToM) is involved in decision making in strategic games with adults, while its results with children are still controversial, probably because the literature to date has not directly assessed children's concept of fairness. The goal of this research is to investigate what constitutes fairness across different age groups (children aged seven, eight and nine years) by assessing both their judgements and their decisions concerning the offers made by a social partner and then to relate this to ToM understanding by using second-order false-belief tasks. Results show that, across age groups, the concept of fairness evolves from divisions in one's advantage towards those of equality; although ToM is not related to the concept of fairness, it plays a role in the strategic behaviour that orients children to accept more equal divisions and to reject hyperfair divisions.