The ability to deal with themes most would find offensive or anerving.
1. The ability to deal with a movie or painting in which nudity is shown(NOT porn) without laughing, feeling uncomfortable or making a dirty comment.
2. The ability to deal with swearing in an appropriate manner. IE. not swearing every four seconds when a swear word has no reason for being there. Also, the ability to not be shocked by a swear word, nor laugh or make a joke.
3. The ability to have a conversation about themes most would find offensive or anerving. Such as nudity in art (movies or pictures. NOT porn.) Or perhaps sex life (Most likely, a mature person is one who does not have a ridiculous amount of one night stands, but rather, has an intimate relationship with one person whom they deeply care for.) or education.
4. Those who can commit to one person are mature.
5. Those who don't see pregnancy as a curse or a trap are mature.
6. Those who are accepting of others who are different from themselves are mature.