Contagious: Why Things Catch On

Awe is an emotional response characterized by a sense of wonder and being in the presence of something greater than oneself. In Contagious, Berger identifies awe as one of the high-arousal emotions that drive social sharing, as people feel compelled to share experiences that inspire this powerful feeling. This emotion often arises in response to experiences of exceptional beauty, scale, or achievement, such as witnessing natural wonders or remarkable human accomplishments. Awe-inspiring content tends to go viral because it creates a strong physiological response and prompts people to share their experiences with others to help them feel similarly moved.

Behavioral residue refers to the physical evidence or traces that remain after someone has performed an action or supported a cause. These lasting markers can take many forms, from reusable shopping bags to wristbands to digital footprints on social media. The concept emphasizes how physical artifacts can continue to spread awareness and influence others even after the initial action is complete. For example, the LiveStrong yellow wristbands served as persistent reminders of cancer support, visible to others long after purchase.