I will also add to the part about lying. Sometimes a mature person will need to lie, in order to protect themselves or others. However, a mature person will rarely lie in order to keep themselves or others out of trouble.

How about adding a part about tattling? Immature people will often tell an adult authority figure about even the most minor incidents. Or at the other extreme, they might never tell an adult authority figure about even the most serious violations, because they fear being accused of tattling. Mature people usually know when they can handle the situation on their own, and when to seek help. For example, a mature person might say things like, “Dan threatened me,” or, “Jane touched me in an area where she’s not supposed to.” But they will very seldom say things like, “Henry cut in line at the drinking fountain,” “Carly took too long at the vending machine, so I couldn’t get a snack,” “or David said this, and I didn’t like it.”