Toxic positivity is dysfunctional emotional management without the full acknowledgment of negative emotions, particularly anger, fear and sadness. Socially, it is the act of dismissing another person's negative emotions by suggesting a positive emotion instead.

Author Susan Cain said that historically boom-and-bust cycles led not only to reverence for successful businessmen, but also to attributing lack of success not to external circumstance but to a failure of character, a form of victim blaming. The result is a culture with a "positivity mandate" - an imperative to act "unfailingly cheerful and positive, like a winner". Social media has made this trend much worse.

Healthy positivity differs from toxic positivity in the way that it acknowledges negative emotions of sadness, anger, and jealousy. It pushes for growth and learning through setbacks and conflicts. On the other hand, toxic positivity arises from an unrealistic expectation of having perfectly happy lives all the time. When this does not happen, people "can feel shame or guilt" by being unable to attain the perfection desired. Accordingly, positivity becomes toxic when a person rejects negative feelings even when they are appropriate. It is believed that one must be happy in all types of situations, ignoring other emotions. As a result of denying these feelings, it can often lead to further unhappiness in the long run.