This stage of development marks a huge shift in your life and your teens as they move into young adulthood. In just a few short years, your teen will go from relying primarily on you for their care and support to transitioning closer to independent adulthood. As a parent, it can be enjoyable to see your once-dependent child grow and mature into an independent adult.

What Should My Child Be Able to Do (by 18 years of age)?

Physical milestones:

  • Both boys and girls are typically fully developed physically by age 18
  • Boys and girls have reached their full height
  • Boys may continue to develop muscles, grow more facial hair, and their voices may deepen more.
  • Acne may still be an issue for both boys and girls

Social-emotional Milestones:

  • Some children will make strides towards independence and greater responsibility. Others may struggle with taking on these tasks.
  • Become more capable of controlling their emotions. Less moody as hormonal shifts subside.
  • Begin to seek intimate relationships, which become a significant aspect of their identity.
  • Have a stronger desire for romantic relationships and sexuality
  • Go through less conflict with parents
  • Show more independence from parents
  • Exhibit a greater capacity for empathy and sharing, as well as the ability to develop more intimate relationships.

Cognitive Milestones:

  • More capable of thinking about and understanding abstract concepts such as morality.
  • Begin to understand other people better 
  • Developing work habits and understanding what does and doesn’t work for them. 
  • Show more concern about the  future, including education and work plans
  • Better able to justify their own decisions, including what they see as right or wrong.

How You Can Help Foster Development

  • Encourage Activities That Foster Adult Skills: Teens in this phase usually jump at the chance to take on some adult-like responsibilities. If your teen is not pursuing these activities on their own, gently encourage a few. Any activity or pursuit that fosters independence and responsibility can be helpful–getting a part-time job, babysitting, taking a leadership role in a group they belong to, or cooking meals for the family. Helping teens build these skills at this point not only prepares them for the future but also provides a great confidence boost.
  • Have a Financial Conversation: As teens approach adulthood, one issue that is sometimes overlooked is financial management skills. By this stage of development, many teens have some experience with money management, having earned money through part-time jobs. This is a great time to have some intentional discussions about handling money. Explain to teens what your family’s approach to financial issues is and the values you’d like to pass on to them. Don’t be afraid to tell them about any financial mistakes you’ve made so they can avoid making the same ones.Of course, teens will manage their finances in their own unique way, but having a basic awareness of the challenges they may face is beneficial.

Common Challenges Parents Experience During This Period

  • Concerns/anxieties about teens leaving home. While not all teens leave home at age 18, for those that plan to do so, parents can feel a mix of emotions. While parents are most likely proud and excited about their teen’s future plans, they may also experience some worry as their child now enters the adult world. As a parent, it might be easy to allow all the “what if’s” to run through one’s mind. Instead, parents can try to focus on all the ways they have adequately prepared their child for this big transition. Parents can remind themselves of all the responsibilities their children are already taking on and hope that it will only continue as they move into adulthood. 
  • Balancing Letting Go With Offering Help: While many parents look forward to the day when their child is most independent and is making their own decisions, it can be challenging to know how much guidance to offer. Although 17–18-year-olds are making many of their own decisions, some parents may not agree with all of their decisions. Parents are then faced with the choice to either step in or simply allow their child (now an adult) to live their own independent life without their assistance. Every family is different and must navigate this transition period in their own way. However, some experts recommend that parents take on more of a “consulting” role during this time. They can provide some guidance, listen to their young adult children, and perhaps even discuss the steps of making various adult decisions. However, in the end, the emerging adult in their midst (their teen) is ultimately responsible for their own actions and the consequences of those decisions.
Growth and Development

Common Myths During this Period/What NOT to Believe

  • Once a Teen Turns 18, They are Mature and Will Have All the Necessary Adult Skills: While in some countries, 18 is legally considered the age of adulthood, developmentally speaking, an 18-year-old may or may not have all the skills needed to manage adulthood. As discussed in this series, aspects of children’s brains do not fully mature until age 25. That is, the prefrontal cortex, which controls higher-order thinking, planning, and organization, may not be completely online when a child reaches age 18. Similarly, some 18-year-olds may lack the emotional maturity and life experience necessary to control their emotions effectively or make good decisions. Although teens at this stage may be considered adults by legal standards, many still have a lot of maturing ahead of them.
  • All Teens are Unkind: Although the teen years of development can be a bit bumpy with brain changes or hormonal fluctuations, this does not mean that the corresponding behavior changes will lead to unkindness. With guidance and modeling, older teens have the potential to be as kind as anyone else. In fact, some research has shown that, with some encouragement, teens will actually complete acts of kindness quite willingly. Parents can model and encourage kindness in their teens so that it becomes a lifelong habit.

Common Challenges Parents Experience During this Period

  • Next stage planning: Perhaps one of the most significant transitions during this phase of development is helping your child plan for their next phase of life. Once teens graduate from high school, most will need to have plans for further education or a career path. Teens and parents will now work together on primary decisions, but it’s helpful to have parental guidance. By the late-teen years, children will have gained a lot of maturity but still do not have the life experience to foresee the consequences of different life choices. As mentioned above, parents’ roles during this time turn more toward that of consultant and guide than primary decision-maker.

It can be challenging for parents to shift gears and allow their now-young adult children to take on more of the decision-making role for major life choices. Of course, many parents still play a large role in decision-making at this point due to financial decisions and educational paths. Where possible, it’s useful to allow teens to make decisions that will affect their lives directly. Parents can encourage open conversation about choices and guide teens in thinking through their decisions.

  • Balancing Boundaries and Independence: As older teens approach young adulthood, challenges can arise over what boundaries or rules they still need to follow. Although they may be considered adults (at least in some ways), if they are still residing in your home, then certain boundaries and rules are still in place. This can be a difficult balance, especially if your teen is making choices or doing things that break your usual house rules. Some older teens may feel emboldened to act in new ways with the assumption that your boundaries no longer matter. In these situations, it can be helpful to re-establish clear boundaries and expectations for behavior in your home. Be open about what, if any, expectations have changed now that your teen is older and try to come to some agreements about boundaries.


As the teen years end and adulthood begins, it marks a big transition for both parents and children. By allowing older teens more and more independence and decision-making authority, parents can help prepare their children well for the adult world. During this transition, older teens still need support and guidance from their parents so as to avoid dangerous situations and make smart life choices.

The information provided on this site is NOT medical advice and is for informational purposes only. It is not intended to diagnose, provide medical or behavioral advice, treat, prevent, or cure any disease, condition, or behavior. You should consult with a qualified healthcare professional regarding your child’s development, to make a medical diagnosis, determine a treatment for a medical condition, or obtain other related advice.

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