Physical differences lead to people being described primarily in terms of two sexes, man and woman (with a relatively small but fairly continuous distribution of people with intermediate physical characteristics who are referred to as intersexual). This language is influenced by the view that sex refers to physiology and gender refers to social role; not everyone agrees about this usage, and the terms male and female are sometimes used both ways.
The difference is most apparent in the genitals, which are located at or within the groin and are part of the sexual reproductive organs. For women, most of the reproductive organs are within the lower abdominal cavity, with some external parts; for men, most of the organs are external, with a few parts within the abdomen. Mature females also have breasts, which are equipped to manufacture milk and to make the milk accessible to an infant.
The body produces steroidal and other hormones with a variety of effects, related in part to sexual function. The roles of these hormones are under continuing study.
Puberty is the beginning of sexual maturity and the process of becoming capable of reproducing sexually. Body changes at puberty can include appearance of body hair in both sexes and, in men, larynx growth resulting in deepening of the voice. For women, ovulation (egg production = fertility) and the menstrual cycle begin, along with development of breasts and with some modification of body shape to facilitate childbearing and birth. In men the production of sperm (fertility) and of semen (the fluid that carries the sperm) begins. Young persons also experience emotional changes and changes in social interactions at this stage.
The survival of any species requires reproduction. For animals using sexual reproduction (such as humans), puberty strengthens urges toward sexual contact designed to produce offspring. In order that reproduction will be highly likely, sexual contact has evolved to be enjoyable enough (and its absence uncomfortable enough) that almost everyone who has reached puberty is pretty interested in satisfying the urge for it.
Different human cultures have widely varying customs surrounding sexual contact and the circumstances under which it is viewed as acceptable. These include the age and emotional maturity of the individuals, the possibility or desirability of pregnancy, and any significant difference in age of partners. One needs to think about the reasons for these views and customs in order to be in a position to help one's society act on the basis of reason and information rather than of superstition, prejudice, or misinformation.
Humans vary in the specifics of their sexual preference (or orientation). Persons who are attracted sexually to those of the opposite sex (by far the most usual situation) are called heterosexual (straight); persons attracted to those of the same sex are called homosexual (gay; lesbian); persons attracted to those of both sexes are called bisexual (bi). It is currently estimated that about 1 - 2 % of the population is homosexual (1% of the U.S. population is about three million people).
Homosexuality and other non-heterosexualities are currently much discussed in society. Conflicting views exist about what (if anything at all) public policy regarding these should be. The discussion seems to divide mainly in two ways: the first involves disagreement about whether homosexuality comes with one's body (genetic), if it results from one's life experiences and choices (environmental), or both; the second is whether it makes sense to say, whatever the origin of the orientation, that such an orientation is in some sense wrong or immoral.
What underlies such debates? Those who disapprove of orientations that are other than unambiguously heterosexual might think they constitute either an illness (to be cured) or an inappropriate choice (to be forbidden and/or corrected). Others think that it should not be an issue of approval or disapproval but rather one of understanding and accepting the well-observed range of variation in what it is to be human and trying to treat everyone as fairly as possible.
Incidentally, there seems to be growing consensus that separation of attributes of life in terms of nature and nurture is often doomed to failure and that variability among humans includes as normal a more or less continuous spectrum of physical, emotional, intellectual, etc., characteristics.
During much of the last century any discussion of homosexuality was nearly taboo; considerable progress has been made since then. Much of the current public policy discussion is focused on the issue of whether it is fair to prevent homosexual couples from the relationship of marriage. Part of the problem is that some religions are not willing to agree to such marriages for reasons having to do with their own dogma, which is within their right as regards marriages they perform. A possible solution is to agree that civil marriage can occur between mature couples of any sexual orientation, conveying all civil rights that legally attach to marriage, while additional religious marriage under any particular religion, conveying of itself no civil rights whatever but perhaps also incorporating civil marriage, can occur entirely at the discretion of those who make the rules for the religion. An alternative might be to create separate so-called civil unions; fairness suggests that they should entail all the legal rights conveyed by marriage.
Sexual contact is a source of physical pleasure because evolution has naturally reinforced the tendency for the species to survive. It is not surprising that people also want to have sexual contact for the purpose of pleasure and/or as an expression of love or affection for a partner. Often there is reason to be interested in avoiding pregnancy, which would ordinarily result in the birth of a baby.
Becoming a parent entails becoming responsible for the health, safety, and general welfare of a human being (the baby, who is otherwise helpless). Helping this new person to reach the status of an independent citizen is a process that in ordinary cases is expected to take at least eighteen years of effort, attention, and expense, not to mention in the best cases loving devotion to the process. Adolescents who unexpectedly become parents often find the experience, whatever its considerable rewards, one that diverts them from life goals and dreams they might have had. It has been said that teen parenthood is one of the surer routes to a lifetime of relative poverty, since not unusually one or both of the parents is deflected from planned education into the need to work immediately to support the family. Work begun under urgent circumstances might not lead to the same kinds of lifetime opportunities as could be afforded by a more planned start to work life.
Since there are also a number of sexually transmitted diseases (often called STDs; examples are HIV-AIDS, syphilis, gonorrhea, Chlamydia, and genital herpes), there are additional reasons for being well informed about possible consequences of sexual contact and about methods of avoiding STDs (some of which are identical to methods for avoiding pregnancy).
Some families and some religions have reservations about some or all of the currently available methods for preventing the production of unwanted offspring and/or protection against STDs. It's important to know what these methods are, since it is only by knowing options that one can choose whether or not to use any of them.
Many methods are used to attempt to prevent pregnancy. These includeavoiding sexual intercourse (abstinence);There are also emergency methods for attempting to prevent pregnancy after sexual intercourse has occurred (Plan B and some alternatives); these are often colloquially called morning after methods, although the idea is to use them as soon as feasible (within 72 hours is recommended for Plan B) if necessary. Every young person should make it his or her business to be well informed about these methods whether or not need for any of them is anticipated.
avoiding sexual intercourse during the woman's fertile period (fertility awareness);
interrupting sexual intercourse before fertilization can occur (withdrawal);
the woman's use of chemical methods (oral contraception—the pill—or injection);
barrier methods that prevent sperm from reaching the egg (male and female condoms, female diaphragms, cervical caps, and a few others);
chemicals meant to kill sperm before it can reach an egg (spermicides);
mechanical devices placed in the woman's uterus (intra-uterine contraceptive device or IUCD);
male surgery to block sperm (vasectomy);
female surgery to prevent eggs from reaching the uterus (tubal ligation).
Some barrier methods (such as condoms) are also used to try to prevent the spread of STDs. Use of male or female condoms or abstinence are the only methods effective both against pregnancy and against STDs.
Having no more than one sexual partner in any significant period of time is believed to be one of the safer methods for avoiding STDs (assuming the partner is also being—as this is called—serially monogamous).
Some unintended and/or unwanted pregnancies come about in spite of the existence of these methods for avoiding them. It is possible to terminate a pregnancy surgically by removing the embryo or fetus from the uterus (abortion).
Most people regard abortion as undesirable in principle, in that it occurs late enough in the cycle of potential reproduction that an initially extremely low probability event (fertilization of a particular egg by a particular sperm) has already occurred. Now that medical arts are developed to the point that most pregnancies result in a successful birth and now that infant mortality is relatively low in most countries, some people insist that the embryo or the fetus is more than a potential person, rather is in some sense an actual person, even though the embryo or fetus would not be capable of surviving—being viable—outside the uterus. Some religions are particularly taken with this point of view.
While most persons who object to abortion recognize that exceptions in the case of rape (forced sex) or the health of the pregnant woman are justified, some persons insist that abortion is never justified — that even if the mother is sure to die, the pregnancy should continue if the fetus can be expected to reach a viable stage.
In recent times the argument in favor of availability of abortion has centered on two main points: unwanted children should not be brought into the world (since the expectation that they would have a life of decent quality is small), and women should ultimately be able to decide what happens to their own bodies, including pregnancy and childbirth.
Many people believe that abortion should be both infrequent in practice and easily available when really needed. Both education and general attention to public health will have to improve in order that this state of affairs may be achieved. There is no reason to believe that vigorous opponents of abortion will soon change their minds, however, since the points mentioned above do not appear to convince them.
Another matter that also concerns young people is sexual abuse. It is important that sexual contact always be between people both of whom desire the contact and both of whom are mature enough to understand the possible consequences, both physical and emotional. As mentioned above, different societies have different opinions about the age and circumstances under which sexual contact is regarded as potentially appropriate, but most western societies regard the passage of some years beyond the onset of puberty to be important for the development of perspective and judgment.
Sexual contact of older persons with young persons who have not reached puberty (pedophilia) and/or have not progressed to some further emotional and/or legal maturity (statutory rape) is not acceptable and is appropriately regarded as criminal; young people need to be aware both thatsuch contact, whether from a relative, family friend, or stranger, is not acceptableThis kind of abuse is never the fault of the young person, whatever his or her role in the contact.
such contact must be reported to a responsible and sympathetic adult, even if that person has to be outside one's family (such as a school official, church official, police officer, or family friend, unless the perpetrator is a member of the same group).
Finally, western society has developed in such a way that frank discussion of matters relating to sex has been very difficult until rather late in the previous century. Because of this, many people avoid explicit discussions of sexuality, STDs, and birth control. Further, various media features have developed, such as advertising and pornography, that manipulate people's curiosity about sexual matters for the purpose of financial gain. Some advertising exploits people's unease about their possible attractiveness as well as exploiting their response to sexual stimuli for marketing purposes. Pornography presents images of sex that crudely exploit sexual curiosity.
As people become more comfortable with discussion of sexual matters, it is reasonable to expect both forms of exploitation to become less common (or at least less crude).