To explore attribution bias in PD population, the Ambiguous Intentions Hostility Questionnaire (AIHQ) developed by Combs (2007) will be used. The participants will be asked to read 15 vignettes, to imagine the scenario happening to her or him (e.g., ''You walk past a bunch of teenagers at a mall and you hear them start to laugh''), and to write down the reason why the other person (or persons) acted that way toward you. Two independent raters will subsequently code this written response for the purpose of computing a ''hostility index'' (described below). The participant will then rate, on Likert scales, whether the other person (or persons) performed the action on purpose (1 ''definitely no'' to 6 ''definitely yes''), how angry it would make them feel (1 ''not at all angry'' to 5 ''very angry''), and how much they would blame the other person (or persons) (1 ''not at all'' to 5 ''very much''). Finally, the participant will be asked to write down how she or he would respond to the situation, which will be later coded by two independent raters to compute an ''aggression index'' (described in Combs, 2007).