With the rise of infodemics, tackling the spread of misinformation has become a critical global issue. We conducted two online experiments (Study 1, N = 2363; Study 2, N = 1858) to investigate whether kin and reciprocal altruism increase intentions to share news articles on childhood vaccine safety. Target recipients varied among family members, friends, and distant others. Intentions to share news articles via several communication media were higher for vaccine-related real-positive (e.g., childhood vaccination-activated immunity), real-negative (e.g., childhood vaccination-caused side effects), and fake-negative (e.g., myocarditis after childhood vaccination is a higher risk than the disease itself) news than for vaccine-unrelated news. Kin and reciprocal altruism fostered intentions to share all types of news articles with all target groups. These findings highlight the psychological drive to share dubious information from an evolutionary perspective, indicating that such sharing may be triggered by altruistic motivations in daily life. The possibility of effective interventions targeting altruists to reduce the spread of misinformation is also discussed.
Chen et al. (2026) studied this question.