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Normative Sexual Behavior

Childhood sexual health exploration in the form of play is natural and healthy, and involves sexual behaviors that:

  • Occur spontaneously and intermittently,
  • Are not the sole focus of children's play, the interest in sex play is balanced by other interests and activities,
  • Involve children who are willing to engage in OR are generally light hearted and playful,
  • Are agreed upon (that is, no child is objecting to the behavior),
  • Do not cause any of the children strong uncomfortable feelings, such as anger, shame, fear, or anxiety,
  • Are not coercive, and
  • Often decrease with appropriate caregiver intervention when the child receives nurturing instructions to stop the behaviors

Sex Play Among Children

  • Occurs among children of similar age and ability who know and play with each other, rather than between new acquaintances or strangers,
  • Often occurs between children of the same-gender and can include siblings,
  • Is a common occurrence in childhood, and
  • Among preschool aged children sex play may include showing private parts to other children and touching other children's private parts in an exploratory way.

In particular, typical sexual behaviors of younger children do not include more advanced adult-like sex behaviors.

In adolescents, some "normative" sex behaviors that include more advanced sex activities may be defined as problematic and illegal by family or cultural norms or state and federal laws.

When working with parents or other caregivers, professionals should emphasize the importance of remaining calm and provide information about caregiver responses for typical sex behaviors.

For more information about caregiver responses to typical sexual behaviors please see Childhood Sexual Development

(For additional relevant information see Assessment (Coming Soon), Clinical Decision-Making, and Intervention (Coming Soon)

Sibling Sexual Experiences

How do you know if sibling sexual experiences are normative or concerning? 

  • Retrospective research indicates sibling sexual experiences among children is common.
  • Behaviors may start as normative sex play (due to curiosity) among siblings--but when these experiences are too frequent, one-sided, or coercive--this is cause for concern and intervention
  • Research indicates sibling sexual experiences are the least reported and the least investigated sexual behaviors among adolescents.
  • Females may be more vulnerable to exploitative sibling sexual experiences than males.


When siblings who are close in age are involved, additional challenges arise when determining the level of concern about the sexual behavior. What may have started as sexual play from mutual curiosity, can evolve to something more one-sided and coercive. Children in these situations may feel confused, blame themselves, or feel insecure. Telling an adult about problematic sexual behaviors of siblings is difficult. 

What do professionals need to know about sibling sexual experiences?

  • Categorizing behaviors as sex play or a distinctly abusive event is not always easy. Professionals report that sibling sexual abuse is increasing, yet parents may not have observed, or may misunderstand, minimize or ignore these behaviors.
  • Reviewing the sibling sexual behavior conceptual continuum helps professionals understand the differences between expected sex play, problematic sexual behavior, and abusive sexual behavior.
  • Helping parents and caregivers understand how to respond to typical sexual behavior is important. If sex play is typical, professionals should encourage parents and caregivers to talk with their children about their bodies and behaviors (e.g., information about respecting their own and others' bodies). See Childhood Sexual Development
  • When inappropriate or abusive sexual behavior occurs, professionals need to intervene. Professionals need to consider risk and protective factors and the impact of the problematic behaviors on the children and caregivers when determining the need for a child's removal, the supervision plan, a treatment approach, and visitation/reunification decisions.

Sibling Sexual Behavior: A Conceptual Continuum (Bonner and Chaffin)

Click below for more information about:

(For additional relevant information see Assessment (Coming Soon)Clinical Decision-Making, and Intervention (Coming Soon)

Normative Sex Knowledge and Behaviors by Age

Preschool Aged Children 3-5 Years
Physical Development in children in the preschool years is a time of growth and developing competency in gross and fine motor coordination. Supervision and guidance for children in this age group is needed because their judgement and problem-solving skills are just beginning to be developed. They are constantly moving and learn through involvement in activities.

Sexual Knowledge

  • Children as young as 3 years of age can identify their own gender, and then soon after identify the gender of others. Initially distinctions between genders are based on visual factors found in the culture (such as hairstyles, size, or clothing), though by age 3 or 4 many are aware of genital differences. Gender roles are not set this early and children display a range of behaviors culturally associated with either or both genders.
  • Preschool children's understanding of pregnancy and birth tends to be vague until about age 6.
  • Knowledge of adult sex behavior is most often limited to behaviors such as kissing and cuddling until about age 6 years when perhaps a quarter of children report knowledge of more explicit adult sexual behavior.

Sexual Behavior
Preschool children are curious in general and tend to actively learn about the world through listening, looking, touching, and imitating. Preschool children's general curiosity about the world manifests with questions as well as exploratory and imitative behaviors including sex body parts. These sexual behaviors often occur in public and include:

  • Looking at others when they are undressing or nude,
  • Intruding on others' physical boundaries (e.g., standing too close to others),
  • Showing private parts (e.g., being "silly" or not knowing rules about privacy),
  • Touching their own genitalia, and
  • Touching adults' breasts (particularly their mother's).

Some children dress or play in ways culturally considered to be of the opposite sex--this is normal and not considered a sexual behavior.

Children's touching of their own private parts is not the same behavior as what adults view as "masturbation." They may touch their private parts if they itch or if they are exploring their own body. Young children seek experiences that are calming and pleasant, such as, they suck their thumb, they rub on soft blankets, and they periodically touch their private parts because it feels good.

There are several sex behaviors that are NOT normative in preschool children. These include intrusive, planned, or aggressive sex acts, putting their mouth on another child's sex parts, and pretending toys are having sex. Problematic Sexual Behavior

School Aged Children 6-12 Years

Physical Development
Girls often begin puberty earlier than boys and breast development can start as early as 7 or 8 years of age. Boys and girls progress through five stages of puberty but the onset and length of time in each stage varies based primarily on race and gender. Early or delayed onset of puberty can have a significant impact on the social adjustment of youth.

Sexual Knowledge
Knowledge of pregnancy, birth, and adult sex activity expands greatly during the school-age period and may influence sexual behaviors. By age 10, most youth have a basic understanding of puberty, reproductive processes, and child birth. The accuracy of children's knowledge depends on their exposure to correct informal and formal educational material.

Sexual Behavior
School-age children's sexual behaviors become more guided by societal rules.

  • Sexual behavior, including sex play, continues to occur throughout the school-age period. The behavior tends to be more concealed and caregivers may not be aware of the children's behavior.
  • School-age children become increasingly more interested in media and are more likely to seek out television and pictures that include sexual behavior and nudity. (American Psychological Association report on the impact of media on the sexualization of girls.)
  • Self-touch and masturbatory behaviors occur among girls and boys equally, with an increase in frequency particularly among boys during this developmental period.
  • Modesty emerges during this developmental period, particularly with girls who often become shy and private about undressing and hygiene activities.
  • Sexual attraction to same age peers increases near the end of this developmental period with interactive behaviors typically beginning with playful teasing of others. Few children are involved in more explicit sex activities including sexual intercourse at the end of this developmental period (on average 6% of children under 13 years of age report sexual intercourse. For more information, see the Centers for Disease Control and Prevention survey of youth risk behavior).

Further information on school age children and puberty can be found at the American Academy of Pediatrics website and the Adolescent section below.

Adolescence Ages 13-19 Years

Adolescence may be conceptualized as a dramatic time of child development spanning the second ten years of life. Puberty and other significant physical, social, emotional, and intellectual changes, and sexual development, mark this ever fluctuating and sometimes emotionally unstable period of life. Significant brain development occurs during adolescence with rapid growth and related cognitive, social-emotional, and behavioral changes continuing until the early to mid-twenties.

Physical & Sex Development
During adolescence, pubertal development continues. For most youth, physical growth is complete by mid adolescence (for more information, click here.)

Adolescent sexual development includes not only physical changes, but the development of oneself as a sexual being. Adolescents becoming increasingly aware of their sexual attractions and interests, including sexual orientation and gender identity.

Young Adolescents
School children and young adolescents ages 9 to 13 may experience a substantial increase in sexual thoughts and feelings. One's first feelings of sexual attraction may occur as early as 9 to 12 years of age with onset of sexual fantasies occurring several months to one year later. This development may be followed by a "surge" of sexual interest and attractions. The physiological changes associated with puberty include increased levels of sex hormones further impact feelings of sexual arousal, attraction, and fantasies. Nocturnal emissions and the onset of menstruation are signs that the adolescent as reproductive capability. (See here for more information on adolescent sexual pubertal and sexual development and early, mid- and late adolescent stages.)

Middle and Late Adolescence
By middle adolescence, which generally includes youth between 13 and 16 years, physical puberty may be almost complete. During this time sexual thoughts and feelings as well as sexual behavior expand further. In late adolescence, which typically includes 17 to 19 year olds, sexual thoughts, feelings, and activities may continue to significantly increase. For example, youth may become involved in a relationship that includes sexual intimacy. Brain development does not cease at age 18 or 19 and significant social-emotional and intellectual growth relevant for healthy and pro-social behaviors can be expected to continue.

Developmental differences between young adolescents and older adolescents have been noted in brain growth, as well as in their social, emotional and behavioral repertoires. Despite these overall patterns, it also is important to consider the tremendous variation in developmental milestones among teens. Further, there may be "mismatches" in the rates of development across domains for individual youth. For example, a girl may begin puberty at 9 but not yet have developed the higher order cognitive skills necessary for managing social and sexual situations that may arise. Thus, age is not always the best indicator of social maturity and good judgement.

Differences between adolescents' cognitive and social functioning and those of adults are of great importance. When compared to adults, adolescents:

  • Are more impulsive,
  • Are more likely to take risks,
  • Have poorer judgement,
  • Are more susceptible to peer influences, and
  • Are less able to consider the future consequences of their actions.

Adolescents may also be less capable of accurately identifying the emotions or intentions of others, resulting in misinterpretations that can contribute to inappropriate responses or behavior. For example, if a boy touches a girl's breast in the hall at school and she says, "Stop that!" but laughs as she says it, he may be unclear what she means.

Professionals must keep in mind that adolescents are trying to understand the rapid sexual development of their feelings and bodies. Adolescents may have advanced sexual knowledge and experience but may be well behind in abstract thinking and understanding the impact of their behaviors on others. As adolescents mature, they are able to understand and interpret their own sexual feelings and the emotions and behaviors of others.

Sexual Knowledge
The extent and accuracy of an adolescent's knowledge about sexual matters is determined by a variety of factors including parent-child relationship quality, family attitudes and knowledge, the availability of school-based sex education programs, Internet and publicly available written literature, and cultural factors.

  • Peers are a "go to" resource for most teens and, frequently, are a source of inaccurate and misleading information, such as overestimates of the degree to which others in the group are engaging in sexual activity.
  • Exposure to sexual and violent stereotypes, such as movies and music that depict girls and women as sex objects and portray manliness as associated with sexual conquests, may promote distorted attitudes about normal and healthy sexual behavior.
  • Open communication between adolescents and their parents/caregivers concerning sexuality and healthy sexual behavior is a key to facilitate the acquisition of accurate information. Early communication provided before the initiation of sexual behavior is important to lay the foundation for future dialogue.

The extent to which other information sources provide accurate and sufficient information varies considerably. Education and accurate information ensuring that sexual activities are consensual and consistent with relevant state laws may be limited or lacking.

Sexual Behavior
During early adolescence there is an increase in sexual behaviors which often involve self-exploration and masturbation. Some experimentation may involve opposite or same gender peers. While these behaviors often occur with mutual agreement, they may be motivated by self-interest more than reciprocal in nature. Same gender sexual activity may be related to curiosity, opportunity, or sexual orientation. Sexual orientations are not considered sexual behavior problems.

The frequency of sexual activity increases in mid-adolescence. Many males begin masturbating to ejaculation between ages 13-15 years; the onset of masturbation in females is more gradual.

In contrast with early adolescence, mid adolescent sexual relationships may involve increased emotional intimacy and not be as self-focused. With late adolescents, the frequency of sexual activities increases. Most sex is within dating or romantic relationships, but much occurs outside these relationships as well. Sex outside romantic relationships generally is more likely in boys and is associated with other risk factors, although casual sex among late adolescents and young adults ranging from kissing to sexual intercourse, such as "hooking up," has become more common.

In sum, throughout adolescence, sexual activities may include the following, with the more advanced behaviors more likely in older adolescents:

  • Sexually explicit conversations with peers,
  • Obscenities and jokes within cultural norm,
  • Sexual innuendo, flirting, and courtship,
  • Interest in erotica; pornography use, and sexting*,
  • Solitary masturbation,
  • Hugging, kissing, holding hands,
  • Making out, fondling*
  • Mutual masturbation*
  • Oral sex or intercourse with consenting partner*

*Note: Moral, social, or familial rules may limit or forbid these behaviors. Some state laws make sexual behaviors illegal.

Perhaps contrary to the expectation of some, sexual intercourse and oral sex are common during adolescence. Youth often are between 15 and 17 when they first engage in intercourse with the median just over 16 years. Nearly 50% of high school students and more than 60% of 12th graders have engaged in sexual intercourse. Compared to Whites and Latinos, the onset of sexual intercourse is earlier for African-American males and later for Asian Americans. For more information, see the Center for Disease Control and Prevention survey of youth risk behavior). Most sexual activity is within dating or romantic relationships, but much occurs outside these relationships as well. Although sexual intercourse during teen years is not unusual, it is not always socially appropriate or even legal. Further, there are considerable risks and consequences to these sexual behaviors which are the topic of sex education and prevention programs (See Sex Education Resources)

Next: Problematic Sexual Behavior