Disclosed herein is a robot including at least one of a display or a speaker, at least one sensor configured to detect a physical stimulus, and a processor configured to detect a first physical stimulus based on a first sensing value acquired from the at least one sensor and output a first interface representing a first emotion corresponding to the first physical stimulus via at least one of the display or the speaker. The processor is configured to detect repetition of the first physical stimulus based on at least one sensing value sequentially acquired from the at least one sensor and output an interface representing an emotion equal to or different from the first emotion via at least one of the display or the speaker, whenever the repeated first physical stimulus is detected.