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Growth and Development, Ages 18 and Over-What Parents Need to Know

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Human development is a lifelong process of physical, behavioral, cognitive, and emotional growth and change. In the early stages of life—from babyhood to childhood, childhood to adolescence, and adolescence to adulthood—enormous changes take place. Throughout the process, each person develops attitudes and values that guide choices, relationships, and understanding.

Sexuality is also a lifelong process. Infants, children, teens, and adults are sexual beings. Just as it is important to enhance a young adult’s physical, emotional, and cognitive growth, so it is important to lay foundations for his/her sexual growth. Adults have a responsibility to help young people understand and accept their evolving sexuality.

Each stage of development encompasses specific markers. The following developmental guidelines apply to most youth in this age group. However, each young person is an individual and may reach these stages of development earlier or later than others the same age. When concerns arise about a specific young adult’s development, parents or other caregivers should consult a doctor or other developmental professional.

Physical Development

Most young adults aged 18 and over will:

  • Complete the process of physical maturation, usually attaining full adult height [Secondary sexual characteristics, such as size of penis and breasts, are completed.]

Cognitive Development

Most young adults aged 18 and over will:

  • Move into adult roles and responsibilities and may learn a trade, work, and/or pursue higher education
  • Fully understand abstract concepts and be aware of consequences and personal limitations
  • Identify career goals and prepare to achieve them
  • Secure their autonomy and build and test their decision making skills
  • Develop new skills, hobbies, and adult interests

Emotional Development

Most young adults aged 18 and over will:

  • Move into adult relationships with their parents
  • See the peer group as less important as a determinant of behavior
  • Feel empathetic
  • Have greater intimacy skills
  • Complete their values framework
  • Carry some feelings of invincibility
  • Establish their body image

Sexual Development

Most young adults aged 18 and over will:

  • Enter into intimate sexual and emotional relationships
  • Understand their own sexual orientation, although they may still experiment
  • Understand sexuality as connected to commitment and planning for the future
  • Shift their emphasis from self to others
  • Experience more intense sexuality

What Families Need to Do to Raise Sexually Healthy Young Adults

To help young adults ages 18 and over develop a healthy sexuality, families should:

  • Keep the lines of communication open and accept that the person is an adult, not a child.
  • Offer choices, acknowledge responsibilities, and avoid dictates.
  • Continue to offer physical and emotional closeness, but respect their need for privacy and independence.
  • Appreciate them for their strengths and qualities.
  • Facilitate their access to sexual and reproductive health care.
  • Continue offering guidance and sharing values.

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