The effects of source credibility and content objectivity on pro‐environmental post engagement on social media: A case study of Chinese <scp>TikTok</scp> (Douyin)

Abstract Social media has become a primary channel for disseminating environmental information aimed at raising pro‐environmental awareness. Post engagement plays a crucial role in effective information dissemination; therefore, environmentalists, government organizations and environmental protection agencies are increasingly focusing on enhancing pro‐environmental post engagement on social media. This study applies the heuristic‐systematic model to examine the effects of source credibility—a heuristic cue—and content objectivity—a systematic cue—on pro‐environmental post engagement. Using 700 short videos from the Chinese TikTok (Douyin) platform, we empirically tested the proposed model. The results show that source credibility positively influences pro‐environmental post engagement, whereas content objectivity negatively impacts pro‐environmental post engagement, with a more significant effect than source credibility. Furthermore, this study reveals that content objectivity weakens the relationship between source credibility and pro‐environmental post engagement. These findings provide empirical support for the attenuation effect in the heuristic‐systematic model, demonstrating that when heuristic and systematic cues exert opposing influences on post engagement, systematic processing inhibits heuristic processing.