This study examines the relationship between reputational threat and altruistic behavior in children aged 6-11 and explores how social inhibition and group relationships affect this behavior. Study 1 involved 204 children and found that age and reputational threat influence altruism, with age 8 being a key turning point. Study 2 focused on 130 nine-year-olds and showed that children with low social inhibition engage in more altruistic acts, regardless of reputational threat. Study 3, with 151 participants, analyzed the effects of group dynamics based on left-behind status. Non-left-behind children preferred out-group altruism, while left-behind children showed in-group preference under reputational threat, with no difference in its absence. Left-behind children were generally more altruistic. The findings highlight age 8 as crucial for reputation strategies and suggest that reputational threat, social inhibition, and group dynamics shape altruistic behavior. This research offers insights into the positive qualities of left-behind children, informing their development and education.