•  The onset of the coronavirus pandemic in China led to a 74% drop in overall emotional well-being.
•  Factors associated with the likelihood of contracting the disease (e.g., residing near the epicenter), extent of potential harm (e.g., being an elderly), and relational concerns (e.g., those within a marriage) exacerbated the detrimental effect of the outbreak on psychological well-being.
•  Regardless of the actual amount of knowledge they possessed, those perceiving themselves as more knowledgeable about the coronavirus, were able to experience more happiness during the outbreak.
•  Higher perceived knowledge was associated with a stronger sense of control, which mediated the differences in emotional well-being.