18-Year-Old Child Development Milestones

Your child’s growth and development at age 18

By age 18, many teens are feeling a combination of excitement and fear about the future. They tend to be very focused on their friends, social lives, and future. There are a lot of decisions to be made about life after graduation, including potential careers, college plans, or military service paths. Many 18-year-olds invest a lot of time into thinking about what type of life they want once they're on their own, but they also may just be enjoying the present.

Parenting your 18-year-old can be a tricky balance of guiding them towards autonomy while also keeping them safe and supported. "Teenagers can be all gas and no breaks, and that’s scary, which is why it's so important to keep an open, honest dialog with them," says Aliza Pressman, PhD, a professor of pediatrics and psychologist at Mount Sinai Kravis Children’s Hospital in New York City.

Teens who have plenty of life skills often feel ready to move out of the home and begin the next chapter. But others may feel less than ready for life as an adult. Those who are less mature or experience self-doubt may regress a bit as they think about entering the next phase of their lives. Here's what you need to know about your 18-year-old.

18 year old development milestones
Illustration by Emily Roberts, Verywell

18-Year-Old Language and Cognitive Milestones

By age 18, teens exhibit a lot of adult-like thinking, such as complex, abstract thinking and have real, rational goals, says Jennifer Woods, MD, medical director of adolescent medicine at Children’s Hospital Colorado and professor of pediatrics at the University of Colorado School of Medicine. They’re also often future-oriented and able to understand, plan, and pursue long-range goals.

"Support these developing critical thinking and planning skills by asking lots of questions and helping them brainstorm," suggests Dr. Pressman. However, generally, at this age, 18-year-olds should be taking the reigns on most of their problem-solving and big and small life choices.

"They have reached adult legal capacity and are fully able to consent to their own care and make adult decisions," says Dr. Woods. However, note that some 18-year-olds will experience a lot of worry around realizing that they are legally considered an adult but aren’t sure what their life goals and plans are. 

They may feel overwhelmed at times when people ask them what they’re going to do with their lives. Some kids may know exactly what they want for their future, while others may not have solid ideas. This range is normal, but most teens can still use some guidance on how to reach their personal, career, military service, and/or college goals.

"While 18-year-olds may look like adults physically, it is important to remember that the brain is not finishing maturing until about age 25 years, which definitely affects emotional and cognitive development," explains Dr. Woods.

The teens who read the most are likely to have more expansive vocabularies. By now, they’re able to communicate like other adults, although they may just say their first thought before thinking it through as critically as adults do, says Dr. Pressman. They often have similar hobbies and interests as other adults, such as playing sports, using technology, doing art projects, and playing and listening to music.

Language and Cognitive Checklist

  • Able to make their own schedule and plans
  • Are often philosophical and idealistic
  • Increasing capacity to use insight and empathy
  • Makes future plans
  • Sets limits and compromises when appropriate
  • Works toward long-term goals

18-Year-Old Physical Milestones

By age 18, physical development is nearly complete, says Dr. Woods. For most kids, puberty is over and they’ve usually reached their full height. However, some teens, particularly boys, may continue to grow over the next few years.

"As female adolescents begin puberty sooner than males, on average, their physical changes are almost certainly complete, although male adolescents at 18 years may grow a couple of inches taller," says Dr. Woods. 

Boys may also continue to grow a little more facial hair and their voices may still change a bit more. Your teen may continue to fill out a bit more and their hand-eye coordination and gross motor skills may adjust (and improve) over time as they get more used to their mature physiques. Many kids do not spend adequate time (ideally 60 minutes daily) doing physical activity, but doing so will improve health, mood, and energy levels and help them feel at home in their bodies.

"This age is also important as it sets the stage fully for adult habits of exercise and eating well to help prevent common medical conditions such as heart disease, hypertension, diabetes, and obesity," says Dr. Woods.

Teens still need a lot of sleep, from eight to 10 hours per night. Healthy sleep habits are important and include sleeping in a dark, quiet, uncluttered bedroom and keeping electronics off-limits during resting hours. Also, be aware that stress, inadequate nutrition, and lack of sleep can impact a fully developed body more so than it does for younger teens. "It can become harder to bounce back when we don’t get enough sleep, skip meals, don’t exercise, or suffer from stress," says Dr. Woods.

Eighteen-year-olds may be experimenting with romantic relationships and their sexuality. Make sure your teen knows they are loved and accepted regardless of their sexuality or gender identity, says Dr. Pressman. Many teens grow more comfortable with their bodies as they’ve had some time to adjust to the rapid changes they experienced during the earlier teen years.

Physical Milestone Checklist

  • Growth has tapered or ended completely
  • Less preoccupation with body changes
  • Have reached sexual maturity
  • Take care of own personal hygiene and grooming

18-Year-Old Emotional and Social Milestones

Eighteen-year-olds are beginning to figure out where they will fit into the adult world. It is a time for big changes that comes with a lot of freedom and happiness, along with feelings of nostalgia and apprehension.

"The new level of independence brings many changes including moving away from home, transitioning education, moving into the workforce, etc.," says Dr. Woods.

Most 18-year-olds are more comfortable seeking advice from older people and their parents again. They realize that they need some guidance and help to navigate the adult world and they’re likely more open to feedback than they were during their younger teen years. However, they also seek out feedback from their peers.

Older teens have much better control over their emotions at this age. And most 18-year-olds are equipped to deal with a wide variety of emotions. They likely have developed good coping skills by now, including ways to handle stress. That said, it's still common for older teens to get overwhelmed or need help handling any big issues that come their way, such as deciding which career path to follow, navigating issues with their friends, or picking which college to attend.

Fear of the future—as well as fear of failure—can be very real at this age. Some 18-year-olds will begin to resolve these fears early on, while others will continue to struggle well into their adult lives. Be there to offer support, connect them with resources, and provide love and acceptance when you see them having a hard time, advises Dr. Pressman.

Peer groups have less of a pull on 18-year-olds than they did in middle school but are still very important. "Eighteen-year-olds have moved more to an individual friend model over large peer group model and value self-identity and goals over a group mentality," explains Dr. Woods. They’re better able to evaluate their opinions without adopting the same ideas as everyone around them. Many of them take strong stances on social issues, as well.

Most 18-year-olds enjoy spending time and talking with their friends. They also speak differently to their peers than they do to their family members or teachers. Older teens may use a fair amount of slang and they’re usually adept at using social media acronyms. They understand the context and when or where certain behavior or language is and is not acceptable.

Eighteen-year-olds have an emerging ability to make independent ​decisions and to compromise. This serves them well as they are forming new friendships and intimate relationships. Many 18-year-olds have had intimate relationships, and they tend to have a better understanding and awareness of their sexuality at this age. While most of them aren’t ready to settle with a partner, many of them are beginning to think about what they want in a future mate.

Emotional and Social Checklist

  • Able to evaluate their own opinions instead of going along with the crowd
  • Able to manage emotions in a socially acceptable manner
  • Accepts adult responsibilities
  • Intimate and peer relationships are important
  • More comfortable seeking adult advice

Other Milestones for Your 18-Year-Old

Your 18-year-old may be concerned with morality. They may be continuing to evaluate their values and the type of life they want to live as an adult.

Your teen may also be thinking about their spiritual beliefs. It’s normal to question the beliefs they held during childhood and to consider if they want to continue practicing a certain religion or carrying out certain spiritual activities in adulthood.

"There may also be a struggle as they feel independent in many situations but may still be financially tied to parents to support education, housing, insurance, and more," says Dr. Woods.

How to Help Your 18-Year-Old Learn and Grow

Talk to your teen about friendships beyond high school, suggests Dr. Pressman. Discuss whether your teen thinks they’ll maintain some of their current friendships after high school. Talk about meeting new friends down the road while also honoring some of their friendships from the past.

Keep the lines of communication open between you and your child. Rather than try to solve their problems for them, aim to be a sounding board. Before offering advice, suggests Dr. Pressman, ask if they want it. If not, simply listen and ask questions.

While you do want to step in with guidance and support when it's truly needed, it's important to let your child be independent—and even to fail, in order for them to truly mature. "Allow your child to experience the consequences of their actions," explains Dr. Pressman.

It’s normal to experience a sense of grief as your child turns into an adult. Make sure you don’t allow the sadness you might experience to burden your child, and make it clear that although it will be a big change for you, you’re also happy that your child will be heading out into the real world.

Wherever your 18-year-old is developmentally, and no matter how independent they may seem, don't think your job is done. "Remember, you are still the parent and they still need you," says Pressman.

How to Keep Your 18-Year-Old Safe

Many 18-year-olds think they’re alone in their fears. They may compare themselves to their peers or people they see on social media and feel inadequate as a result. They may think they're the only kid without a solid plan for the future. Remind them that they don’t have to have every aspect of their future career planned out—and that what they see online is often highly curated and most often doesn't reflect real life, says Dr. Pressman. "Normalize your teen’s emotions."

Also, remind your teen that their brain isn’t yet fully developed. Drinking alcohol, smoking pot, or doing other recreational drugs at this age could affect their brain development. "Set clear expectations around drug and alcohol use and let them know they can always use you as an excuse to not participate in questionable or unsafe activities," says Dr. Pressman.

Make sure your teen knows they can always call you for a ride or for help. "You don’t want kids to be operating on trying not to get in trouble with you and hiding things or not calling you, as that puts them at risk of getting into really dangerous situations," says Dr. Pressman.

Also, be sure to talk to your child about safe sex and being a respectful partner. Creating safe, healthy boundaries for themselves is an important topic to explore with your child. These boundaries include with other people but also with themselves, such as following healthy schedules for sleep, exercise, eating, work, and play.

When to Be Concerned About Your 18-Year-Old

Changes in appetite, ongoing body image issues, behavior changes, academic issues, discontinuing activities they used to enjoy, or changes in sleep patterns could be signs your teen is experiencing a mental health issue. Substance abuse issues may also become a problem at this age.

"Remember that mental health presents in teens in different ways than in adults," says Dr. Pressman. Depression in teenagers can look a lot like anger and anxiety can make kids have poor behavior. "So, if your teen is having volatile behavior, they may be telling you that they are struggling, and as their parent, if you can recognize this, you can step in to help."

Dr. Woods concurs: "It is important to recognize that the prevalence of mental health disorders (anxiety, depression) increase significantly during late adolescence into early adulthood (ages 20 to 24) and account for the highest burden of disease in this age group."

If you are concerned about your teen’s development, encourage them to talk to their healthcare provider or a counselor. Support their efforts in scheduling an appointment and be willing to go with them to the appointment to talk about any concerns you have.

A Word From Verywell

Even though your child has turned 18, your parenting work is far from over. However, you’ll find that your relationship will shift. Instead of being the disciplinarian, you can take on more of a role of mentor, guide, and sounding board.

You’ll likely watch your teen mature a lot in the coming years. Life experience, whether it’s a job, college, or the military, will give your teen the opportunity to sharpen the skills you’ve taught them and become a mature adult.

Originally written by
Amy Morin, LCSW
Amy Morin

Amy Morin, LCSW, is the Editor-in-Chief of Verywell Mind. She's also a psychotherapist, international bestselling author and host of the The Verywell Mind Podcast.

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