Does intentionality decision-making depend on who you are? The role of individual differences.

Intentionality attribution is a critical ability in everyday life, necessary for attributing meaning to others’ actions. Any impairment in its ascription has been shown to produce significant difficulties in the handling of one’s social life. Recent evidence has indicated that healthy individuals may exhibit systematic bias in their assessment of other people’s intentions: when presented with the negative side effect of an action, the majority of people tend to judge it as intentionally performed, as opposed to a positive side effect (Knobe Effect).Recent research has considered the role of the individual characteristics of the person who judges in order to explain this effect. The experiments included in this dissertation aim to explore the role of certain individual differences strongly associated with intentionality attribution. Specifically, Study 1 revealed that individual production of downward counterfactuals decreases intentionality attributions, whereas upward ones increase them. Study 2 explored the role of individual differences in Theory of Mind (ToM) ability, finding that higher ToM allows individuals to focus on information about the intentions of the agent, reducing attention towards side effects and thus the Knobe Effect. Study 3 confirmed this result, showing that individuals with autistic personality traits tend to over-attribute intentionality to the side effects, due to their reduced attention to intentions. Finally, Study 4 explored the influence of individual ability in processing emotions, by testing individuals with alexithymic personality traits who, conversely, are less influenced by the side effect information and reduce the intentionality attributed to them. In summary, according to their individual characteristics, people focus their attention on different elements (e.g.intentions-side effects) while analyzing social situations, which are consequently perceived in different ways. Future conceptual models of intentionality should take into greater account the influence of individual differences in determining which elements people focus on when ascribing meaning to others’ actions.