Sex education involves the teaching of useful knowledge and related skills of critical issues related to sexuality, including intimacy, human relationships, sexual identity and gender roles, reproductive anatomy and body image, puberty and the reproductive process, emotional aspects of maturation, the value of continued abstinence among teens who are not sexually active, alternative methods of contraception and HIV/STD (sexually transmitted disease) prevention, and the health consequences of avoiding contraceptives and prevention methods among sexually active youth.

Studies show that adolescent sexuality is most influenced by parents, followed by peers, and finally, by what is learned in schools.

Sex education developed in response to various studies showing high rates of teen involvement in sexual activity (75 percent by the college years) and low rates of contraceptive use and knowledge about sexually transmitted diseases (STDs).

Risky Sexual Practices
Further, these studies showed that several situational factors contribute to risky practices among teens — especially failure to plan in advance for sexual activity (on the assumption that planning for sex damages spontaneity and romance) and use of alcohol and/or drugs prior to or during sex.

Also, less than complete ability to assess the potential consequences of one's actions has been found to be common among teenagers. All of these factors are associated with low levels of condom use among teens, and usually all are addressed in sex education programs.

The primary goal of school-based sex education is the promotion of sexual health. To achieve this goal, most programs seek to provide accurate information about human sexuality, an opportunity for value clarification, skills to improve interpersonal relationships, and assistance in exercising responsibility in one's sexual life, including acquiring healthy behaviors and attitudes regarding sexual behavior.

Effectiveness of Sex Education Mixed
Studies of the effectiveness of sex education in achieving its goals have been mixed. Consistently, sex education has been found to increase teenager knowledge about sexual issues, provide modeling and practice to enhance interpersonal skills relative to sexual behavior, and reinforce appropriate values, but most approaches have not had the desired impact on actual sexual behavior or contraceptive use.

Some of the best results are found in education programs that are linked to school-based health clinics. Studies show that sex education is most effective when it is implemented prior to the onset of sexual activity, and when it combines both abstinence and contraceptive information.