In the Myers-Briggs Type Indicator (MBTI), and introvert (I) is a person who prefers to process thoughts internally. Introverts tend to think before they speak. It is contrasted with extroversion. In common use, an introvert is someone who doesn't socialise often. This can be interperated to say that they are judging on the MBTI, for they must get at least slightly anxious in social situations to not socialise often. Introversion by no means predicts one to be judging, however.