The study aims to investigate biases associated with socio-cognitive and psychosocial variables related to misinformation. It is of particular interest to examine cognitive reflexivity, metacognitive awareness, ingroup identification, political ideologies, and religiosity as predictor variables associated with both the identification of misinformation messages and the intention to share them. An online experiment was conducted with 328 university students (49% women) to estimate the presence of the illusory truth bias and the effect of inoculation conditions. Participants were assigned to one of three cognitive inoculation conditions (individual evaluation, metacognition, or control condition) and read various false and true messages related to politics and public affairs. Our results have revealed the presence of the illusory truth effect in the Costa Rican sample. Individuals with higher metacognitive awareness were less affected by the illusory truth bias when evaluating both false and true messages. Participants who tend to identify with their ingroup were more likely to perceive false messages as true. The findings did not demonstrate a substantial reduction of the bias with the inoculation conditions.The study aims to investigate biases associated with socio-cognitive and psychosocial variables related to misinformation. It is of particular interest to examine cognitive reflexivity, metacognitive awareness, ingroup identification, political ideologies, and religiosity as predictor variables associated with both the identification of misinformation messages and the intention to share them. An online experiment was conducted with 328 university students (49% women) to estimate the presence of the illusory truth bias and the effect of inoculation conditions. Participants were assigned to one of three cognitive inoculation conditions (individual evaluation, metacognition, or control condition) and read various false and true messages related to politics and public affairs. Our results have revealed the presence of the illusory truth effect in the Costa Rican sample. Individuals with higher metacognitive awareness were less affected by the illusory truth bias when evaluating both false and true messages. Participants who tend to identify with their ingroup were more likely to perceive false messages as true. The findings did not demonstrate a substantial reduction of the bias with the inoculation conditions.O estudo tem como objetivo investigar os vieses ligados às variáveissociocognitivas e psicossociais relacionadas à desinformação. Pretende examinar a reflexão cognitiva, a consciência metacognitiva, a identificação endogrupal, as ideologias políticas e a religiosidade como preditores associados à identificação de desinformação e à intenção de partilhar. Foi realizada uma experiência online com 328 estudantes universitários (49% mulheres) para determinar a presençade preconceitos de verdade ilusória e o efeito das condições de inoculação. Osparticipantes foram designados para uma das três condições de inoculação cognitiva (avaliação individual, metacognição ou controle) e leram noticias falsas e verdadeiras sobre política e questões públicas. Os resultados revelaram a presença do efeito da verdade ilusória. Os indivíduos com maior consciência metacognitiva foram menos afetados por viés de verdade ilusória ao avaliarem mensagens falsas e verdadeiras.Os participantes identificados com o seu grupo têm maior probabilidade de perceber as mensagens falsas como verdadeiras. Os resultados não demonstraram uma redução substancial no viés com as condições de inoculação.