Research in the field of attitude change has focused primarily on the individual process of information processing of message content. However, pioneering research by Kurt Lewin and studies on mass communication effects suggest that discussion in groups should make available to participants alternative information so as to induce a more critical analysis of arguments. Two studies are presented in which elaboration processes of message content of subjects in group vs. individually are confronted. We hypothesised that being exposed to a persuasive communication in group (vs. being exposed individually) induces a deeper content processing even in subjects who have a low implication in the topic of the message. This should translate into a stronger resistance or a larger change of attitude at the post-test. Results from the first experiment show that subjects exposed in group report higher index of cognitive elaboration than subjects exposed individually. A stronger resistance to the attitude change follows a deeper elaboration. The evidence from the second study seems to indicate that this is the result of the comparison of the different points of view which are available during the discussion.