Perceived Importance of Information: The Effects of Mentioning Information, Shared Information Bias, Ownership Bias, Reiteration, and Confirmation Bias

Participants were given information for and against the decriminalization of marijuana and discussed the issue in groups. Factors affecting rated importance of information after the group discussion were examined. Participants did not rate information that was mentioned during the discussion as more important than information not mentioned, and participants did not rate shared information they mentioned as more important than unshared information. Participants did rate shared information other group members mentioned as more important than unshared information others mentioned. Participants did not rate their own information as more important than other's information, and information that was repeated was not rated as more important. Participants did perceive information supporting their individual position as more important than information against their position, and this confirmation bias was lessened in groups containing an opinion minority. A comparison of minority and majority members in minority-containing groups found that minority members were more open to information than majority members.