In the following set of words, which is different than the others?

Question

Quizplus · Accepted Answer

Mute is an adjective used to describe complete silence, lack of speech, or an absence of sound. It is not similar to the other words in the set because it is not a personality trait, and a person cannot necessarily choose to be mute.
Timid is an adjective used to describe a lack of courage or confidence. It is similar to the other words in the set (excluding 'mute') since they are ways to describe people who are silent or shy as a personality trait, or due to a given situation.
Bashful is an adjective used to describe a reluctance in drawing attention to oneself.
Shy is an adjective used to describe a nervous or timid nature, especially in the company of other people.
Sheepish is an adjective used to describe a feeling of embarrassment from shame or lack of self-confidence.

In the Following Set of Words, Which Is Different Than