Maturity often reflects the learned control a person displays toward the stressors of adult life. Control is exercised over impulsivity, inappropriate responses and the recognition of inadequate preparation or knowledge. As noted by Jerome Bruner in his 1972 article in American Psychologist, immaturity plays an important role, as well. The state of immaturity aides in creating an acceptable space and time to develop the skills and education necessary to function as a successful adult. The process of moving from immature young adulthood to full adulthood is an opportunity for the body and mind to fully develop while responsibility for actions and consequences shifts from dependency to independence. For the young adult, this process can sometimes feel like a confusing struggle.
Organize your bedroom by removing everything and starting over. Strip down any immature wall art (like posters) and spackle the holes. Paint the walls of your room an adult, neutral color. Bring back your bed, desk, bookcases and dresser and limit your decorations to what you need in the present. Put your trophies and childhood objects in well-labeled boxes and store them. Self-care/self-management is the first step of maturity.
Organize your clothing and closet. Remove dated, overly-young clothing and anything that is worn, torn, ragged or emblazoned with offensive or inappropriate art or words. Keep a few casual outfits and make note of what you need for a more-adult appearance. Donate old clothing to charity. Maturity is developed by practicing behaviors.
Get up in the morning at "business" time. This should be between 7-9 a.m. You should be able to do this without prompting by other adults. Clean and dress yourself in clothing that is more adult, the type of clothing you might wear to church or to a job. If you are going to work, wear work-appropriate clothing. The way you look influences the way you behave.
Make your bed properly so that your sheets are tidy and your blankets are straight. Toss any dirty clothing in a laundry basket so you can wash them later. Your room should be tidy and clean with no dirty dishes, unwashed clothing or dirty floors. All of these steps demonstrate self-maintenance. By choosing not to rely on others (parents) and by establishing your ability to take good care of yourself, your belongings, and your personal space, you are demonstrating maturity. Ask to learn how to do basic self-care like laundry and dishes if you don't know how to do them.
Greet other members of your household in a cheerful manner. Make and eat your breakfast. Clean up your dishes. If you notice other chores to be handled such as removal of garbage or other dishes, complete those tasks without prompting from other adults. Emulate the adult behavior that you would like to present for yourself.
Exit your home to attend to your business. You may be in school or college or going to work. If you have a vehicle, it should be well maintained. Adults will constantly challenge your state of reaction since a state of maturity is often observable in action. If you must be prompted or told to do simple maintenance tasks such as taking care of yourself, then you are not mature. Recognize when your behavior is inappropriate. Take on self-management.
Practice pausing when someone tries to provoke you. The first reactions in your body come from ancient primal emotional and instinctive triggers in your amygdala (a part of the brain). The second reaction emerges from your frontal cortex. It is the second reaction that demonstrates maturity. The second reaction emerges from thought and choice, both, features of adult acceptance of personal responsibility for one's actions.
Accept what you don't know. Observe the actions and processes of other adults and try to ask mature questions about what you don't understand. Not knowing and not asking or hiding your lack of knowledge is immature. Adults know that they never know enough and intelligence is demonstrated by not being afraid to learn from others. Embrace humility.
Accept responsibility for your actions. Reacting to threats, jokes, pokes, jabs, bullying or any behavior by other people is a way to demonstrate immaturity. Reactions without thinking are to be avoided. The actions of others do not justify immature responses from you. Don't create meaning for what others do. The actions of others emerge from their personal issues and choices and don't have anything to do with you unless you accept or receive those actions (a form of immature agreement).
Execute your business to the very best of your ability. Whether you attend school, work at a job, or volunteer, the way you value your work and how it reflects on your personhood is observable by other adults. Being trustworthy, thoughtful and sincere are important. Take action to do what needs to be done to improve the quality of your business.
Treat others as you wish to be treated. If you cannot treat others with respect, humility and dignity, then you demonstrate that you do not believe that you should be treated that way. Keep in mind that maturing is a process of choice and work. It takes work to develop the skills not to react emotionally as if you were a child. This doesn't means your emotions aren't valid, it simply means that you can choose how your emotions inform your behavior and choices. During the day take notes on moments where you acted appropriately and when you didn't. Reflect on these later and ask other adults to help you solve issues so that your next confrontation will be managed in a more useful manner.
Managing all of the details to live a positive and meaningful life is difficult to learn. Maturity is an adoption of the skills and learning necessary to accomplish this type of management and control. In addition, it is the full development of the body such that the activities of adulthood can be managed. This involves muscular development as well as cognitive development.
It is possible to get stuck at a behavioral age due to a trauma or to an unwillingness to mature and to take on responsibility. If you sabotage yourself frequently, then you may benefit from discussing your inability to mature with a qualified counselor or a wise adult you can trust.