In this study, we explore the effect of diversity among people who share a story about a scientific discovery, on the recipient’s credibility assessment regarding that story. The data used in this study were gathered in two phases. Initial data were collected through the Twitter application program interface. The data were then used in an experimental setting: We manipulated the level of diversity of real-life Twitter followings, supposedly retweeting a story to our participants (n = 274). Each of our participants was then asked to complete a paper-based survey. Our findings show that social diversity can enhance the perceived credibility of a shared item. This effect is amplified among individuals with high digital literacy, as well as individuals with high need for cognition. The study offers a deeper understanding of credibility assessment mechanisms within Twitter and other social networking sites.