Chinese idiom · 成语
喜怒无常
Meaning
Joy and anger unpredictable; erratic emotions.
Character by character
Origin and story
historical accountThe Book of Wei uses this expression in its biography of the general Yang Dayan. While describing the campaign at the Huai embankment, the historian says that his delight and anger became unpredictable and that he punished soldiers excessively, leaving them resentful. This is a judgment about a commander's conduct and its effect on those under him, rather than a separate fable about changing moods. Later usage applies the same phrase to someone whose pleasant manner can abruptly turn to anger. Its critical force lies in that unreliability, not simply in experiencing different emotions.
Sources and further reading
In everyday life
经理最近喜怒无常，大家开会时都格外小心。
The manager has been unpredictable lately, so everyone is especially careful during meetings.
A critical description of unpredictable shifts between friendliness and anger, not a clinical diagnosis.