Biological Factors

Although human sexuality has come to serve many functions in addition to reproduction, its biological basis remains fundamental to the sexual experience. Sexual response involves psychological processing of information, which is influenced by learning, physiological responses and brain mechanisms which link the information processing to the physiological response. Although there is much that is not well understood about this complex sequence, it is understood that individuals vary considerably in their capacity for physical sexual response. This variability can be explained only in part by cultural factors. The role of early learning or genetic factors, or an interaction between the two, remains to be determined by further research.

Reproductive hormones are clearly important. However, their role is best understood and most predictable for men-and much more complex for women. For example, apart from the fact that women may experience a variety of reproduction-related experiences--the menstrual cycle, pregnancy, lactation, the menopause, and hormonal contraception-all of which can influence their sexual lives, there does appear to be greater variability among women in the impact of reproductive hormones on their sexuality (Bancroft, 1987). In addition, variations in the onset of puberty and menstruation can represent special challenges for girls in some populations.

Parents and Other Family Members

A number of family factors are known to be associated with adolescent sexual behavior and the risk of pregnancy. Adolescents living with a single parent are more likely to have had sexual intercourse than those living with both biological parents (Miller, 1998). Having older siblings may also influencethe risk of adolescent pregnancy, particularly if the older siblings have had sexual intercourse, and if an older sister has experienced an adolescent pregnancy or birth (East, 1996; Widmer, 1997). For girls, the experience of sexual abuse in the family as a child or adolescent is linked to increased risk of adolescent pregnancy (Browning, 1997; Roosa, 1997; Miller, 1998). In addition, adolescents whose parents have higher education and income are more likely both to postpone sexual intercourse and to use contraception if they do engage in sexual intercourse (Miller, 1998).

The quality of the parent-child relationship is also significant. Close, warm parent-child relationships are associated with both postponement of sexual intercourse and more consistent contraceptive use by sexually active adolescents (Jaccard, 1996; Resnick, 1997). Parental supervision and monitoring of children are also associated with adolescents postponing sexual activity or having fewer sexual partners if they are sexually active (Hogan and Kitagawa, 1985; Miller, 1998; Upchurch et al, 1999). However, parental control can be associated with negative effects if it is excessive or coercive (Miller, 1998).

Schools

Evidence suggests that school attendance reduces adolescent sexual risk-taking behavior. Around the world, as the percentage of girls completing elementary school has increased, adolescent birth rates have decreased. In the United States, youth who have dropped out of school are more likely to initiate sexual activity earlier, fail to use contraception, become pregnant, and give birth (Mauldon and Luker, 1996; Brewster et al, 1998, Manlove, 1998; Darroch et al, 1999). Among youth who are in school, greater involvement with school-including athletics for girls--is related to less sexual risk-taking, including later age of initiation of sex, and lower frequency of sex, pregnancy, and childbearing (Holden et al, 1993; Billy et al, 1994; Resnick et al, 1997).

Schools may have these effects on sexual risk-taking behavior for any of several reasons. Schools structure students' time; they create an environment which discourages unhealthy risk-taking--particularly by increasing interactions between youth and adults; and they affect selection of friends and larger peer groups. Schools can increase belief in the future and help youth plan for higher education and careers, and they can increase students' sense of competence, as well as their communication and refusal skills (Manlove, 1998; Moore et al, 1998).

Schools often have access to training and communications technology that is frequently not available to families or clergy. This is important because parents vary widely in their own knowledge about sexuality, as well as their emotional capacity to explain essential sexual health issues to their children. Schools also provide an opportunity for the kind of positive peer learning that can influence social norms.

The Community

Community can be defined in several ways: through its geographic boundaries; through the predominant racial or ethnic makeup of its members; or through the shared values and practices of its members. Most persons are part of several communities, including neighborhood, school or work, religious affiliation, social groups, or athletic teams. Whatever the definition, community influence on the sexual health of those who comprise it is considerable, as is its role in determining what responsible sexual behavior is, how it is practiced and how it is enforced.

The measurable physical characteristics of neighborhoods and communities, such as economic conditions, racial and ethnic composition, residential stability, level of social disorganization, and service availability have demonstrated associations with the sexual behavior of their residents-initiation of sexual activity, contraceptive use, out-of-wedlock childbearing and risk of STD infection (Billy and Moore, 1992; Brewster et al, 1993; Grady, 1993; Billy et al, 1994; Grady et al, 1998; Tanfer et al, 1999). An understanding of these characteristics and their impact on individuals is important in planning and developing services and other interventions to improve the sexual health and promote the responsible sexual behavior of community residents.

A shared culture, based either on heritage or on beliefs and practices, is another form of community. Each of these communities possesses norms and values about sexuality and these norms and values can influence the sexual health and sexual behavior of community members. For example, strong prohibitions against sex outside of marriage can have protective effects with respect to STD/HIV infection and adolescent pregnancy (Comas-Diaz, 1987; Kulig, 1994; Savage and Tchombe, 1994; Sudarkasa, 1997; Tiongson, 1997; Abraham, 1999; Amaro, 2001). On the other hand, undue emphasis on sexual restraint and modesty can inhibit family discussion about sexuality and perhaps contribute to reluctance to seek sexual and reproductive health care (Hiatt et al, 1996; Schuster et al, 1996; He et al, 1998; Tang et al, 1999). Gender roles that accord higher status and more permissiveness for males and passivity for females can have a negative impact on the sexual health of women if they are unable to protect themselves against unintended pregnancy or STD/HIV infection (Amaro and Raj, 2000; Bowleg et al, 2000; Castaneda, 2000).

When a community--defined by its culture--also has minority status, its members are potential objects of economic or social bias which can have a negative impact on sexual health. Economic inequities, in the form of reduced educational and employment opportunities, and the poverty that often results, has obvious implications for accessing and receiving necessary health education and care. In addition, a history of exploitation has, in some cases, led to distrust and suspicion of public health efforts in some minority communities (Tafoya, 1989; Thomas and Quinn, 1991; Wyatt, 1997).

The Media

The media--whether television, movies, music videos, video games, print, or the Internet-are pervasive in today's world and sexual talk and behavior are frequent and increasingly explicit. More than one-half of the programming on television has sexual content (Cope and Kunkel, in press). Significant proportions of music videos and Hollywood movies also portray sexuality or eroticism (Greenberg et al, 1993; DuRant et al, 1997). Among young people, 10-17 years of age, who regularly use the Internet, one-quarter had encountered unwanted pornography in the past year, and one-fifth had been exposed to unwanted sexual solicitations or approaches through the Internet (Finkelhor et al, 2000).

Media programming rarely depicts sexual behavior in the context of a long-term relationship, use of contraceptives, or the potentially negative consequences of sexual behavior. The media do, however, have the potential for providing sexuality information and education to the public. For example, more than one-half of the high school boys and girls in a national survey said they had learned about birth control, contraception, or preventing pregnancy from television; almost two-thirds of the girls and 40 percent of the boys said they had learned about these topics from magazines (Sutton et al, in press).

While the available research evidence shows a connection between media and information regarding sexuality, it is still inadequate to make the link between media and sexual behavior.

Religion

Simply being affiliated with a religion does not appear to have great effect on sexual behavior; however, the extent of an individual's commitment to a religion or affiliation with certain religious denominations does (Brewster et al, 1998). For example, an adolescent's frequent attendance at religious services is associated with less permissive attitudes about premarital sexual activity and a greater likelihood of abstinence (Ku et al, 1993; Billy et al, 1994; Werner-Wilson, 1998). On the other hand, for adolescents who are sexually active, frequency of attendance is also associated with decreased use of contraceptive methods among girls and increased use by boys (DuRant and Sanders, 1989; Ku et al, 1993).

Health Care Professionals

Physicians, nurses, pharmacists and other health care professionals, often the first point of contact for individuals with sexual health concerns or problems, can have great influence on the sexual health and behavior of their patients. Yet, both adolescents and adults frequently perceive that health care providers are uncomfortable when discussing sexuality and often lack adequate communication skills on this topic (Croft and Asmussen, 1993).

Health care providers typically do not receive adequate training in sexual aspects of health and disease and in taking sexual histories. Ideally, curriculum content should seek to decrease anxiety and personal difficulty with the sexual aspects of health care, increase knowledge, increase awareness of personal biases, and increase tolerance and understanding of the diversity of sexual expression. Although such training for physicians has increased-95 percent of North American medical schools offer curriculum material in sexuality-nearly one-third do not address important topics such as taking a sexual history (Dunn and Alarie, 1997).

The Law

In the United States, the law regulates sexual behavior in complicated ways through criminal, civil, and child welfare law and operates at local, state, and federal levels. Criminal law imposes penalties for certain kinds of sexual activities, considering factors such as age, consent of both parties, the actual act performed, and the location in which it takes place. Civil law complements criminal law and can extend the law's reach. Civil law, for example, provides individuals with protection from sexual harassment and allows legal redress for some victims of sexual violence (Levesque, 1998). It can also have an impact through regulation of relationships such as marriage, divorce, and child custody and support.

The law may also regulate some aspects of the community's influence on sexuality, including the family, schools, and media. While it generally protects parental rights (Levesque, 2000), the law also imposes limits. For example, it protects children from sexual victimization by a family member. The law also regulates access to sexual health services through mechanisms such as parental notification and waiting period requirements. With respect to schools, although states may set certain minimum standards, the law allows individual school systems to determine the content of curriculum, including sexuality education curriculum. In addition, the legal system provides schools with the power to develop and implement programs to address the prevention of sexual harassment, relationship violence, and rape.

Under protection of the First Amendment to the U.S. Constitution, the media have great freedom in the choice of content they portray. At the same time, the law can impose certain restrictions on the media; for example, it may limit minors' access to sexually explicit materials.

Availability of Reproductive Health Services

In the United States, contraceptive and reproductive health services are provided to women and menby a wide range of health care professionals. These services are offered in a variety of settings-private practice offices, publicly funded family planning clinics, private clinics, military clinics, school-based health centers, college and university health centers, and private hospitals. Often, contraceptive services are integrated with other basic preventive health services such as pelvic examinations and pap tests, and screening for sexually transmitted infections (Frost and Bolzan, 1997). In addition to medical care, counseling or education related to sexual and reproductive health may be provided.

Barriers to obtaining these services can exist if providers are not conveniently located, are not available when needed, do not provide (or are thought not to provide) confidential, respectful, culturally sensitive care, or are not affordable (Forrest and Frost, 1996). Federally subsidized family planning services have been an important factor in helping many persons overcome these barriers and avoid an estimated 1.3 million unintended pregnancies per year (Forrest and Samara, 1996).