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Sex

Alternate meaning: Human sexuality, in particular sexual intercourse

The word sex is also used as an abbreviation to refer to sexual intercourse (the physical acts related to sexual reproduction) and other human sexual behavior, but this article will discuss the concept of sex defined above.

Table of contents

1 Sex in fungi, plants 2 Sex in animals 3 Sex in humans 4 Biological varieties of discordance 5 Psychological, behavioral, and cultural varieties of discordance 6 Note on terminology: sex versus gender 7 See also 8 External links and further reading

Sex in fungi, plants

Sex in animals

In mammals, birds, and many other species, sex is determined by the sex chromosomes, called X and Y in mammals, and Z and W in birds. Males typically have one of each (XY), while females typically have two X chromosomes (XX). All individuals have at least one X chromosome, the Y chromosome is generally shorter than the X chromosome with which it is paired, and is absent in some species, this pattern admitting some considerable variation. In birds, males have two of the same kind of sex chromosome (ZZ) and females have one of each type (ZW). In other species, including crocodiles, and most insects, sex may be determined by various other sex-determination systems, including those controlled by environmental factors such as temperature. Yet other species change sex during their lifetime.

Sex in humans

Sex in humans is a unitary concept and identity for most social purposes: we are male or female. However, when the criteria for defining male and female are looked at more closely two important facts become obvious. First, sex is definable at many different levels, some biological, some social, some psychological. Second, a significant fraction of the human population is not entirely concordant in every aspect of every level of definition.

The following table(only for threesomes) outlines some of the major levels at which we recognize a difference between human males and females. Some of the criteria are sex-dichotomous and some, such as body size, are sex dimorphic (i.e., characterize what is statistically more likely for one sex or the other). Some of the levels can be more objectively ascertained and measured than others. Some of the levels are "imputed" or defined by the surrounding society. For instance, whether male humans must wear trousers is a social issue. Some of the levels seem to be generated within each person as a subjective identity or drive.

Level of definition	Female	Male
Biological levels
Chromosomal or genetic sex	XX	XY
Gonadal sex	ovaries	testes
Anatomic sex of external genitalia	clitoris, labia, vagina, perineal urethra	penis, scrotum, phallic urethra, fused perineum
Anatomic sex of internal genitalia	uterus, fallopian tubes	prostate, seminal vesicles
Psychosocial levels
Assigned sex	"It's a girl"	"It's a boy"
Sex of rearing	"You are a girl"	"You are a boy"
Gender identity	"I am a girl/woman"	"I am a boy/man"
Gender role	"female" social behavior	"male" social behavior
Sexual orientation	androphilic	gynephilic

The relationship of the biological levels of sexual differentiation to each other are fairly well understood. Many of the biological levels can be said to cause or determine the next level. For instance, for most people, the presence of a Y chromosome causes the gonads to become testes, which make hormones that cause the internal and external genitalia to become male, which cause the parents to assign and raise the child as a boy. However, the degree to which biological factors and environmental contribute to the psychosocial aspects of sexual differentiation, and even the interrelationships between the various psychosocial aspects of differentiation, are less well understood (the familiar "nature/nurture" controversy).

The second clear fact about human sex and gender is that a significant proportion of the human population is discordant at some levels of this paradigm, meaning that many people do not have every single biological, psychological, behavioral, and social characteristic in the same column.

Some discordances are purely biological, such as when the sex of the chromosomes ("genetic sex") does not match the sex of the external genitalia ("anatomic sex"). This type of discordance is fairly well understood and is described briefly in the next section and more fully in the article on Intersex.

Discordances between the biological and psychosocial levels, such as when the gender identity does not match the anatomic sex, or between the various psychosocial levels, such as when the gender role does not match the gender identity, are even more common but less well understood. These levels of definition and discordance are described below and in individual articles.

Understanding discordance is important for several reasons. People with biological discordances have taught us much about the processes of sexual differentiation, both biological and psychosocial. Some of the levels of discordance have enormous significance to the lives of the those affected and their relationships with society. In some cases, the causes of the discordances have acquired controversial political significance. Societies vary on the values placed on some of discordances. In the last several decades the public consensus of many Western societies has come to view discordances as less undesirable and more tolerable than in the much of the past and much of the rest of the world.

Biological varieties of discordance

Human variability occurs in all the levels by which sex and gender are defined. Discordance at the biological levels is often referred to as an intersex condition. For example, some women may have an XY karyotype (chromosomal constellation). Some boys may have a rudimentary uterus, or an extra X chromosome. In a small subset of boys or girls with intersex conditions, the external genitalia may be undervirilized or overvirilized. If the degree of virilization is "in-between", the genitalia are described as "ambiguous". Many people with intersex conditions do not have ambiguous genitalia. However, for these people the relationships between biological factors (such as hormones) and environmental factors and the psychosocial levels of sexual identity such as gender identity and sexual orientation have proven to be complex, with plenty of exceptions to proposed theoretical systems. For example, there have been cases of male genetic/chromosomal sex, with female external genitalia, assigned and raised as female, but discovering or deciding upon a male gender identity by adolescence. The degree to which a person's gender identity is affected by hormones, by genetic factors distinct from hormones, by early education, by social factors, and by "existential choice" remains imperfectly understood and a subject of contention.

Psychological, behavioral, and cultural varieties of discordance

In contrast to the small percentage of people with biological discordances of sex, a fairly large proportion of human beings may be "discordant" in one or more behavioral or psychological dimensions. The vast majority of these people who are discordant in some aspect of psyche or behavior do not have any detectable biological intersex condition. Human societies respond to, or accommodate, these behavioral and psychological discordances in many different ways, ranging from suppression and denial of difference to acknowledging various forms of "third sex."

It is interesting, and perhaps significant, that some societies identify youths with atypical behavioral characteristics and, instead of giving them corrective therapy or punishing them, socialize them in such a way that their individual characteristics let them provide a needed and/or useful function for the society in a recognized and respected role. (See, for example, shaman, medicine man, tong-ki.)

See the article Pictogram for an example of a pictogram of a man and a woman, to indicate the respective toilets. It shows the man with broader shoulders (sex dimorphism) and the woman in clothing that is in the western world rarely worn by men, a dress (which functions as a gender signal). (Presumably these "male human" and "female human" pictograms are not used in countries where men wear dress-like clothing.) In most societies, it is considered improper for a person of one sex to misrepresent himself or herself as a member of the opposite sex by donning inappropriate clothing (thereby practicing transvestism or, colloquially, cross-dressing). Such behavior receives severe social and/or legal sanctions in some cultures.

See also berdache, hijra, xanith and transgender.)

Note on terminology: sex versus gender

Many people, among them many social scientists, use "sex" to refer to the biological division into male and female, and "gender" to refer to gender roles assigned to people on the basis of their apparent sex and/or other contingent factors; to gender identity, a person's own feeling of belonging to a gender, and to gender perception as a description of how a person's gender is perceived.

See also

• autosome
• evolution
• evolution of sex
• foreplay
• fuck
• gender and sexuality studies
• hermaphrodite
• heteronormativity
• human sexual behavior
• human sexuality
• List of transgender-related topics
• orgasm
• philosophy of sex
• pornography
• pregnancy
• romance
• sexual differentiation
• sexual intercourse
• sexual orientation : heterosexual, homosexual, bisexual.
• sexual repression
• sex organ
• sex and illness
• sexology
• sexual dimorphism
• sexually transmitted diseases
• Why we have sex
• the assembly language mnemonic SEX

• Francoeur, Robert T (Ed.), "The International Encyclopedia of Sexuality" [full text]
• Raymond J. Noonan, Robert T. Francoeur, and Martha Cornog, "Continuum Complete International Encyclopedia of Sexuality". Continuum, August 2003, ISBN 0826414885
• Famous Quotes on Sex
• Sex Dictionary