I'm writing about a mature girl (15ish). But I'm not sure how she should act other than being polite. The way I think a mature person would act would be someone who doesn't swear, but some mature people that I know still do that.
How should I write about a mature girl?
Some ideas I already had:
To me, the biggest components of maturity are
So a mature person is not surprised if a politician is found to be cheating on his wife; affairs among the powerful seem pretty commonplace. Even an observant young girl, with her eyes open, could probably discern this pattern and not be shocked to learn it.
Also, a mature person might still have the impulse to curse out a superior, but control it and be more stoic or careful with what they say or how they respond.
A mature girl might feel the impulse to do something risky or forbidden, but control herself and refrain from it, or refuse to do it.
Maturity is the opposite of Childish. Childish behavior is impulsive and of the moment, it fails to consider consequences and it fails to consider risks, and (related to those) it fails to consider whether a short term gain or pleasure might actually be a terrible thing in the long term.
As Amadeus has stated, impulse control is the greatest attribute of maturity. Additional benefits include...
Maturity is a step along the path to Personal Mastery which is a state where all of the forces and fears of younger life lose all of their power, leaving freedom and opportunity in their wake.
I'd recommend reading up on emotional intelligence. Being high in EI is what I associate with maturity, especially being high in assertiveness.
Goleman lays out the basic traits that make up EI. From Wikipedia:
Self-awareness – the ability to know one's emotions, strengths, weaknesses, drives, values and goals and recognize their impact on others while using gut feelings to guide decisions.
Self-regulation – involves controlling or redirecting one's disruptive emotions and impulses and adapting to changing circumstances.
Social skill – managing relationships to move people in the desired direction
Empathy – considering other people's feelings especially when making decisions
Motivation – being driven to achieve for the sake of achievement
The old adage is, "write what you know." To add to that (and make it more of an encouragement than a rejection), we can also say, "know what you write."
Your own personal observation of people and how they interact and live really is your best tool upon which to draw for vivid, life-like characters.
You can't substitute for that with cut-out descriptions taken from the internet, and you certainly can't substitute for it by reading a psychology textbook. (I won't go into a rant here about the defects of psychology, but let's point out the obvious: most psychologists' interactions with people do not represent people from all walks of life. You're dealing with a very limited subset.)
If you want to write REAL characters, REAL stories (or realistic), and grab onto your readers with your writing, you may want to go outside of your comfort zone in talking to people.
Go and talk to some "mature women." Whatever that means. Talk to people from all walks of life—people living in the streets, people living in posh condos, wandering vagrants, people from foreign countries, people in foreign countries, anybody. See for yourself how they behave and what they do and how they speak and what they think.
It's a lot more work, but you'll wind up with your own inimitable style and viewpoint, and what's more valuable, you'll wind up with a real knowledge of people and relationships.
Lots of great ideas about maturity in the other answers.
Lots of times mature people act the same way as immature people: the differences often only come out under stress. To address the part of your question where you ask how to write about someone who is mature, ask yourself what maturity means to you then push your character into situations where those characteristics come into play. It also helps to contrast your mature character with an immature character. Consider the following (exaggerated) exchange between IG (Immature Girl) and MG (Mature Girl)
IG: You bitch! You stole my boyfriend! You're a smug, phony, self-righteous slut!
MG: Wait, IG, can we talk about this? I can totally see how it would look that way to you. If I thought a friend betrayed me, I'd be really hurt and mad. I wouldn't do that to you. Can you listen to my side?
So here we see IG losing her temper and throwing out insults. MG stays calm, looks at things from IG's viewpoint, and shows empathy and diplomacy. A mature person might also say something like: "oh... I never looked at it like that. I guess you're right and I was wrong. I'm sorry." This demonstrates the emotional maturity necessary to evaluate one's own actions, admit that they were wrong, and accept responsibility for them.
Hope this helps.
Think of a mature adult, then subtract experience. I've known plenty of teenagers in my life that were way more mature than a lot of adults I've known. The one thing they don't have is life, as in quantity of.
