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Sexual Development & Behavior: An Introduction

In order to promote growth and well-being across all areas of development, it’s necessary to have knowledge on the wide range of ways children and adolescents mature. This course will inform you about attitudes and beliefs on sexual development, provide information on typical sexual development and behavior for students spanning kindergarten through high school, and provide guidance on how to support students, families, and staff who encounter issues with student sexual behavior. This lesson introduces you to key terms and provides opportunities to reflect on how experience and culture affect how we think about sexual development and behavior.

  • Reflect on your personal beliefs and cultural view of sexual development and behavior.
  • Define key terms for sexual development and behavior.
  • Understand critical factors to consider when analyzing sexual behavior.



Evaluating Beliefs & Defining Sexual Development

Children and adolescents develop in many ways, and you play an important role in your students’ development. In the school environment, you are especially concerned with development that contributes to cultivating a successful student. Sexual development is like any other area of human development, and you should feel confident in your ability to promote healthy sexual development in students.

When you think of sexual development in students, what comes to mind? Maybe you feel somewhat uncomfortable talking about anything related to sexuality and sexual behavior, or perhaps you think about sexual abuse. Others may think about specific incidents they’ve encountered in their work in schools. There is no right or wrong answer. It’s important, however, to acknowledge that your experience, knowledge, and culture influence how you feel. Take a moment to reflect on the following questions:

  • What opportunities have I had to learn about sexual development?
  • Was sexual development discussed in my family? In my school?
  • How confident am I in my knowledge about sexual development?
  • How comfortable am I discussing sexual development and behavior with students? With families and colleagues?

Many adults, including seasoned educators, have had little or no formal education or professional development on child and adolescent sexual development. This topic may feel inappropriate to talk about because it is often left out of broader discussions on student education and well-being or only discussed from an abuse and prevention perspective.

Because it is not commonly discussed, sexual behavior is often viewed as a problem rather than a normal part of development. Families’ and educators’ lack of opportunities to learn and ask questions about sexual behavior creates stigma—a lack of respect that may cause shame.

To expand your thinking and ease any discomfort you may feel about the topic of sexual development and behavior, you must be able to define it. The following definition will help you understand what this area of development includes and help you view sexual development like other areas of human development.

“Sexual development includes not only the physical changes that occur as children grow, but also the sexual knowledge and beliefs they come to learn and the behaviors they show.” (The National Child Traumatic Stress Network, 2009)

How is the above definition similar or different to what you previously thought about sexual development? Does it help you think about sexual development in a different way?

Continue to think about all of the areas included in the definition—physical changes, knowledge and beliefs, and behaviors—as you learn more and as you observe the students in your school.

The Continuum of Sexual Behavior

If you think about sexual behavior along a continuum, there are three broad types: normative, cautionary, and problematic. These terms are used throughout this course to guide your thinking and support response to student sexual behaviors. Review each description in the table below. While these descriptions provide guidelines, know that the lines between each type are not exact or easy to define. 

The Continuum of Sexual Behavior

Normative "Common"
  • Infrequent and random
  • Developmentally typical
  • Easily redirected
  • No harm to self or others
  • Usually occurs between youth close in age or development who spend time together
Cautionary "Less Common"
  • May be random or planned
  • Developmentally typical but more preoccupation than is typical
  • May not always be redirected
  • May be somewhat disruptive to others
Problematic "Uncommon"
  • Intentional and repeated pattern
  • Advanced for development
  • Difficult to redirect; continues after clear redirection; met with anger or strong emotions
  • Frequently disruptive to others
  • Forced harm to others; use of manipulation
  • Interferes with normal interests, activities, and development
  • May be a large age or developmental gap between youth (2+ years)

To further reflect on sexual behaviors you observe and to determine what action you should take, consider the following student factors:

Culture & Family Norms:

Differences in opinion are the result of the diverse experiences and viewpoints within groups. Some families use child-specific language when they teach their children words for their genitalia. You may have heard families say “pee-pee” to mean penis or vulva; this is a common example of a child-specific word. Other parents and many experts feel it is important for children to learn the correct terms for all body parts. If you are not used to this, it may catch you off guard to hear young students use words such as “breasts” or “scrotum.” Language is one way family norms and culture influence children’s behavior and knowledge of their bodies and sexual development. See the document, Sexual Development and Behavior Terminology, in the Learn section for a list of anatomically correct words and definitions. When thinking about a family’s culture and norms, also consider other factors they have experienced such as trauma, deployment, and their formal and informal supports.


During youth, all behavior, including sexual behavior, is influenced by development. There may be differences between a student’s chronological age and their developmental abilities. A student who is chronologically 8-years-old but has cognitive and social-emotional skills similar to a 4-year-old may not feel shyness or modesty about others seeing their body. If this student frequently walks out of the bathroom with their lower body exposed, you would view this behavior with the understanding that the child’s social-awareness and self-awareness are less like that of an 8-year-old and more like that of a younger child. For this specific student, this may be a normative behavior. If the same behavior were observed in a developmentally typical 8-year-old, however, the behavior would likely be viewed differently.

Function of the Behavior:

When you observe sexual behavior in students you will want to consider the function or reason for the behavior. Think about why the student may have engaged in the behavior and how it benefits them, or what they get out of it. The same behavior in two different students can have different functions. For example, the function of the behavior for a student who creates a sexually explicit drawing following a trauma is different from a student who draws sexually explicit images on another student’s folder to get a reaction from them. Also, think about the cognitive and social-emotional development of students to analyze whether behaviors are reactions to the environment or more planned out occurrences. Even when sexual behaviors appear to be more planned out and intentional, many students, even those in high school, do not fully understand the implications and why they engage in such sexual behavior.

Frequency & Participation:

For most young children, normative sexual behaviors are usually random and infrequent, motivated by curiosity and play. In later developmental stages it’s expected that the frequency or participation in sexual behaviors will increase due to the physiological changes that characterize those years; although, they are less likely to occur in public. Knowing how many times a behavior occurs over a period of time and whether the student limits other activities due to more interest than is typical for sexual behavior will help you think about frequency and participation in the context of individual student’s development.

For example, a 14-year-old student masturbating in private a few times per week is normative sexual behavior because it aligns with their current developmental stage and does not interfere with involvement or participation in other activities. But a 14-year-old student that leaves class several times daily to masturbate in the bathroom may be exhibiting a different type of behavior on the continuum. While there is no definitive line, consider the context of the behavior and how it may influence participation in other activities to help guide your thinking.


When sexual behavior occurs, think about the environment in which the behavior took place. A 12-year-old who self-stimulates only when alone in their bedroom is an example of normative behavior. One’s bedroom is a safe and appropriate place for a child or adolescent to explore their body and sexuality. If the same child were to engage in this behavior in the presence of peers and teachers during school, then you may consider a different type of behavior and action steps. Another important factor to consider is a student’s developmental age. You may know a student’s chronological age, or how many years old they are, however, developmental age is more complicated. A child’s developmental age is the approximate age at which they are functioning. All children and adolescents develop at different rates; some areas of development may be more advanced or more delayed than other areas. It’s important to consider students’ developmental abilities rather than focusing solely on their chronological age. If a sexual behavior were to occur at your school, consider the student’s development and level of functioning before making assumptions based on their chronological age. For example, a 7-year-old student in your class has a language delay, so you may think “His language skills are more similar to a 3-year-old than a 7-year-old.”

Effect on Others:

Think about how sexual behaviors impact others when responding to and creating action plans. A 16-year-old who watches sexually explicit videos on their phone with two close friends has a different effect on others than if the same individual sent a sexually explicit video and images to everyone in his school on social media. Who is affected and how other individuals are affected by the student’s sexual behavior helps you determine how to support. Think about whether involvement was (a) mutual or force or manipulation were used, (b) whether the affected students are annoyed, disturbed, or harmed, and (c) the age, size, and developmental differences of the youth.

Ease of Redirection:

Behavior that is common and typical is easily redirected, meaning that students stop unwanted behavior with developmentally fitting guidance and expectations. This is also true for normative sexual behavior. For example, two 6-year-old students are playing a game of “doctor” or “nurse” and are touching each other’s bodies during recess. Rather than asking them to “stop,” you can redirect them by suggesting more appropriate activities such as taking turns pushing each other on the swings. This provides these students guidance on acceptable touch and play while still fulfilling their need to be physically active. Students with sexual behavior that is outside of normative are less responsive to redirection and may express strong emotions such as anger when redirected.

For adolescents, kissing or hugging is considered a normative sexual behavior and can be redirected. For example, on the way to your classroom you notice two 17-year-old students kissing in the hallway. You remind them that they’re at school and discuss appropriate touch in school settings, such as holding hands instead.

Completing this Course

For more information on what to expect in this course, visit the Focused Topics Sexual Development & Behavior in K-12 Students Course Guide.

Please note that the References & Resources section at the end of each lesson outlines reference sources and resources to find additional information on the topics covered. As you complete lessons, you are not expected to review all the online references available. However, you are welcome to explore the resources further if you have interest, or at the request of an administrator. Also note that Lesson Eight is targeted to faculty and staff who serve in mentor or leadership roles, and Lesson Nine speaks to school administrators.


Listen as school professionals discuss the importance of being aware of your beliefs on students’ sexual development and behavior and how sexual development is a part of human development. What factors or experiences from your childhood and adolescence influence how you think of sexual development as an adult?

An Introduction

Learn how experiences and beliefs influence views on sexual development and behavior.


You have now reflected on your personal beliefs and knowledge on sexual development and behavior and also have a clear definition. Wherever you are in your path of learning, it is important that you have factual information; awareness helps destigmatize sexual behavior in youth and allows educators to better support healthy development. Read the following research-based statements, and reflect on how this information influences your beliefs:

  • Many children demonstrate sexual behavior in peer settings (Phipps-Yonas et al., 1993).
  • Most children will engage in sexual behavior at some point during childhood (Kellogg, 2009).
  • Children with cautionary and problematic sexual behavior have not always been abused (Freidrich, 2001).
  • Using developmentally appropriate information to educate youth about sex does not encourage advanced sexual behavior (Lindberg & Maddow-Zimet, 2012).
  • Children with sexual behavior problems are not younger versions of adult sex offenders (Chaffin et al., 2006).
  • Most children who receive treatment for sexual behavior do not continue the behavior into adolescence or adulthood (Silovsky, Swisher, Widdifield, & Burris, 2012).
  • Approximately 27 percent of teenagers have received a “sext,” or the sharing of sexually explicit images, videos, or messages, and 14 percent of teenagers report they have sent a sext (Madigan, Ly, Rash, Van Ouytsel, & Temple, 2018).
  • In 2017 approximately 39.5 percent of high school students report that they have had sexual intercourse (CDC, 2017).


Choose at least one Case Study below—elementary, middle and high school—and complete the coordinating activities to deepen your knowledge of sexual development and behavior. Share your responses with a member of your school’s leadership team. This activity is intended to help you think about all of the parts of sexual development and the factors that influence sexual behavior. You will have the opportunity to revisit these case studies in later lessons to brainstorm action steps.


Now that you have learned the definition, key terms, and factors to consider for sexual development and behavior, complete the My Knowledge & Beliefs on Sexual Development activity to further reflect on what you know and feel.


chronological age:
Age of person measured from date of birth
To move military personnel from a home installation or base to an assigned duty
formal support:
Help from an organization or professional who is trained to provide a service
Organs of the reproductive system, especially the external organs
informal support:
Help via family and friends who are not paid to do so as part of a job or profession
logical reasoning:
Ability to connect two or more ideas and think about future consequences
Touching and arousing one’s genitals for pleasure; also referred to as masturbation
sexual behavior challenges:
Children ages 12 and younger who initiate behaviors involving sexual body parts (i.e. genitals, anus, buttocks, or breasts) that are developmentally inappropriate or potentially harmful to themselves or others
A strong lack of respect for a person or a group of people or a bad opinion of them because they have done something society does not approve of


What is the National Child Traumatic Stress Network’s definition of sexual development:
True or false? It is easy to determine if a child’s sexual behavior is normative, cautionary, or problematic because these categories of sexual behavior are clear cut and distinct
Identify which statement best describes normative sexual behavior. 
References & Resources

Bancroft, J. (Eds.). (2003). Sexual development in childhood. Bloomington, IN: Indiana University Press.

Centers for Disease Control and Prevention. (2017). Youth risk behavior survey: Data summary & trends report 2007–2017. Retrieved from

Chaffin, M., Berliner, L., Block, R., Cavanaugh Johnson, T., Friedrich, W., Garza Louis, D., . . . Silovsky, J. F. (2006). Report on the task force on children with sexual behavior problems. Findings from the Association for the Treatment of Sexual Abusers. Retrieved from

Counterman, L. & Kirkwood, D. (2013). Understanding healthy sexuality and development in young children. Voices of Practitioners (8)2, 1-13.

Friedrich, W. N., Fisher, J. L., Dittner, C. A., Acton, R., Berliner, L., Butler, J., et al. (2001). Child sexual behavior inventory: Normative, psychiatric, and sexual abuse comparisons. Child Maltreatment, 6(1), 37–49.

Kellog, N.D., Committee on Child Abuse and Neglect. (2009). Clinical report: The evaluation of sexual behaviors in children. Pediatrics (124)3, 992-8.

Lindberg, L.D. & Maddow-Zimet, I. (2012). Consequences of sex education on teen and young adult sexual behaviors and outcomes. Journal of Adolescent Health. 51(4), 332-338.

Lucier-Greer, M., Nichols, L. R., Peterson, C., Burke, B., Quichocho, D. & O’Neal, C.W. (2018). A Brief Guide to Understanding and Responding to Normative and Problematic Sexual Behaviors Among Children. Auburn, AL: Military REACH.

 Madigan, S., Ly, A., Rash, C.L., Van Ouytsel, J., & Temple, J.R. (2018). Prevalence of Multiple Forms of Sexting Behavior Among Youth: A systemic review and meta-analysis. JAMA pediatrics, 172(4), 327-335.

The National Child Traumatic Stress Network & National Center on Sexual Behavior of Youth. (2009). Sexual Development and Behavior in Children—Information for Parents and Caregivers.

Phipps-Yonas, S., Yonas, A., Turner. M., Kamper, M. (1993). Sexuality in Early Childhood: the observations and opinions of family daycare providers. CURA Reporter. (23) 1-5.

Silovsky, J.F., Swisher, L.M., Widdifield, J., & Burris, L. (2012). Clinical Considerations when Children Have Problematic Sexual Behavior. In Handbook of Child Sexual Abuse, pp. 399-428.