Which word characterizes someone showing little emotion?

The word "phlegmatic" aptly describes someone who shows little emotion. It originates from one of the four bodily humors in ancient medicine, which was believed to govern a person's temperament. A phlegmatic individual is often seen as calm, composed, and not easily excited or moved by external stimuli. This quality can manifest as a lack of emotional expression, making the term particularly fitting for someone who remains stoic or indifferent in various situations.

Other choices do not convey the same meaning. "Piquant" refers to something that is stimulating to the taste or mind, typically indicating a level of zest or sharpness, which contrasts sharply with emotional detachment. "Picarist" doesn't have a clear definition in standard English, and it's likely a misspelling or misdirection away from emotional states. "Perfunctory" describes an action carried out with a minimum of effort or reflection, often implying a lack of enthusiasm or interest, which can relate to emotion but is not as directly tied to a person's overall demeanor as "phlegmatic." Therefore, "phlegmatic" is the most precise and suitable choice for characterizing somebody who shows little emotion.