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Romance (love)

Romance or romantic love is a feeling of love for, or a strong attraction towards another person, and the courtship behaviors undertaken by an individual to express those overall feelings and resultant emotions.

The Wiley Blackwell Encyclopedia of Family Studies states that "Romantic love, based on the model of mutual attraction and on a connection between two people that bonds them as a couple, creates the conditions for overturning the model of family and marriage that it engenders." This indicates that romantic love can be the founding of attraction between two people. This term was primarily used by the "western countries after the 1800s were socialized into, love is the necessary prerequisite for starting an intimate relationship and represents the foundation on which to build the next steps in a family."

Alternatively, Collins Dictionary describes romantic love as "an intensity and idealization of a love relationship, in which the other is imbued with extraordinary virtue, beauty, etc., so that the relationship overrides all other considerations, including material ones."

Although the emotions and sensations of romantic love are widely associated with sexual attraction, they could also exist without sexual attraction. In certain cases, romance could even be interpreted as a normal friendship. Historically, the term romance originates with the medieval ideal of chivalry as set out in the literature of chivalric romance.

People who experience little to no romantic attraction are referred to as aromantic.

General definitions
Bode & Kushnick undertook a comprehensive review of romantic love from a biological perspective in 2021. They considered the psychology of romantic love, its mechanisms, development across the lifespan, functions, and evolutionary history. Based on the content of that review, they proposed a biological definition of romantic love:

"Romantic love is a motivational state typically associated with a desire for long-term mating with a particular individual. It occurs across the lifespan and is associated with distinctive cognitive, emotional, behavioral, social, genetic, neural, and endocrine activity in both sexes. Throughout much of the life course, it serves mate choice, courtship, sex, and pair-bonding functions. It is a suite of adaptations and by-products that arose sometime during the recent evolutionary history of humans."

Anthropologist Charles Lindholm defined love as "any intense attraction that involves the idealization of the other, within an erotic context, with expectation of enduring sometime into the future".

Historical usage
The word "romance" comes from the French vernacular where initially it indicated a verse narrative. The word was originally an adverb of Latin origin, "romanicus", meaning "of the Roman style". European medieval vernacular tales, epics, and ballads generally dealt with chivalric adventure, not bringing in the concept of love until late into the seventeenth century. The word romance developed other meanings, such as the early nineteenth century Spanish and Italian definitions of "adventurous" and "passionate", which could intimate both "love affair" and "idealistic quality".

Anthropologists such as Claude Lévi-Strauss show that there were complex forms of courtship in ancient as well as contemporary primitive societies. There may not be evidence, however, that members of such societies formed loving relationships distinct from their established customs in a way that would parallel modern romance. Marriages were often arranged, but the wishes of those to be wed were considered, as affection was important to primitive tribes.

In the majority of primitive societies studied by the anthropologists, the extramarital and premarital relations between men and women were completely free. The members of the temporary couples were sexually attracted to each other more than to anyone else, but in all other respects their relationships had not demonstrated the characteristics of romantic love. In the book of Boris Shipov Theory of Romantic Love the corresponding evidences of anthropologists have been collected. Lewis H. Morgan: "the passion of love was unknown among the barbarians. They are below the sentiment, which is the offspring of civilization and super added refinement of love was unknown among the barbarians." Margaret Mead: "Romantic love as it occurs in our civilisation, inextricably bound up with ideas of monogamy, exclusiveness, jealousy and undeviating fidelity does not occur in Samoa." Bronislaw Malinowski: "Though the social code does not favour romance, romantic elements and imaginative personal attachments are not altogether absent in Trobriand courtship and marriage."

The phenomenon which B. Malinowski calls love, actually has very little in common with the European love: "Thus there is nothing roundabout in a Trobriand wooing; nor do they seek full personal relations, with sexual possession only as a consequence. Simply and directly a meeting is asked for with the avowed intention of sexual gratification. If the invitation is accepted, the satisfaction of the boy's desire eliminates the romantic frame of mind, the craving for the unattainable and mysterious." "an important point is that the pair's community of interest is limited to the sexual relation only. The couple share a bed and nothing else. ... there are no services to be mutually rendered, they have no obligation to help each other in any way..."

The aborigines of Mangaia island of Polynesia, who mastered the English language, used the word "love" with a completely different meaning as compared to that which is usual for the person brought up in the European culture. Donald S. Marshall: "Mangaian informants and co-workers were quite interested in the European concept of "love". English-speaking Mangaians had previously used the term only in a physical sense of sexual desire; to say, "I love you" in English to another person was tantamount to saying, "I want to copulate with you." The components of affection and companionship, which may characterize the European use of the term, puzzled the Mangaians when we discussed the term." "The principal findings that one can draw from an analysis of emotional components of sexual relationship feelings on Mangaia are:
 * 1) There is no cultural connection between a willingness to copulate with a person and any feeling of affection or liking or admiration between copulating partners.
 * 2) The degree of "passion" between two individuals in sexual relationships is not related to an emotional involvement but to degrees of instruction in, and use of, sexual techniques."

Nathaniel Branden claims that by virtue of "the tribal mentality," "in primitive cultures the idea of romantic love did not exist at all. Passionate individual attachments are evidently seen as threatening to tribal values and tribal authority." Dr. Audrey Richards, an anthropologist who lived among the Bemba of Northern Rhodesia in the 1930s, once related to a group of them an English folk-fable about a young prince who climbed glass mountains, crossed chasms, and fought dragons, all to obtain the hand of a maiden he loved. The Bemba were plainly bewildered, but remained silent. Finally an old chief spoke up, voicing the feelings of all present in the simplest of questions: "Why not take another girl?" he asked.

The earliest recorded marriages in Mesopotamia, Greece, Rome, and among Hebrews were used to secure alliances and produce offspring. It was not until the Middle Ages that love began to be a real part of marriage. The marriages that did arise outside of arranged marriage were most often spontaneous relationships. In Ladies of the Leisure Class, Rutgers University professor Bonnie G. Smith depicts courtship and marriage rituals that may be viewed as oppressive to modern people. She writes, "When the young women of the Nord married, they did so without illusions of love and romance. They acted within a framework of concern for the reproduction of bloodlines according to financial, professional, and sometimes political interests."

Anthony Giddens, in The Transformation of Intimacy: Sexuality, Love and Eroticism in Modern Society, states that romantic love introduced the idea of a narrative to an individual's life, and telling a story is a root meaning of the term romance. According to Giddens, the rise of romantic love more or less coincided with the emergence of the novel. It was then that romantic love, associated with freedom and therefore the ideals of romantic love, created the ties between freedom and self-realization.

David R. Shumway states that "the discourse of intimacy" emerged in the last third of the 20th century, intended to explain how marriage and other relationships worked, and making the specific case that emotional closeness is much more important than passion, with intimacy and romance coexisting.

One example of the changes experienced in relationships in the early 21st century was explored by Giddens regarding homosexual relationships. According to Giddens, since homosexuals were not able to marry, they were forced to pioneer more open and negotiated relationships. These kinds of relationships then permeated the heterosexual population.

The origin of romantic love
Anthropologist and author Helen Fisher has argued that romantic love is a mammalian brain system evolved for selecting a preferred mating partner. Fisher's team has proposed that romantic love may have evolved around the time of bipedalism, when new mothers needed additional protection and provision while having to carry their young. A 2023 paper by Adam Bode has argued that while Fisher's evolutionary theory has been the predominant one for 25 years, romantic love could be better explained by evolutionary co-option of the systems for mother-infant bonding. Fisher likens romantic love to mammalian courtship attraction, but Bode argues courtship attraction is separate.

In F. Engels book, The Origin of the Family, Private Property and the State: "monogamy was the only known form of the family under which modern sex love could develop, it does not follow that this love developed, or even predominantly, within it as the mutual love of the spouses. The whole nature of strict monogamian marriage under male domination ruled this out." Sigmund Freud stated, "It can easily be shown that the psychical value of erotic needs is reduced as soon as their satisfaction becomes easy. An obstacle is required in order to heighten libido; and where natural resistances to satisfaction have not been sufficient men have at all times erected conventional ones so as to be able to enjoy love. This is true both of individuals and of nations. In times in which there were no difficulties standing in the way of sexual satisfaction, such as perhaps during the decline of the ancient civilizations, love became worthless and life empty."

Some believe that romantic love evolved independently in multiple cultures. For example, in an article presented by Henry Grunebaum, he argues "therapists mistakenly believe that romantic love is a phenomenon unique to Western cultures and first expressed by the troubadours of the Middle Ages."

Popularization of the term "Romance"
The word "romance" is derived from the Latin adverb Romanice, meaning "in the vernacular," in reference to the languages Old French and Old Occitan. These languages were descendants of Latin, the language of the Romans. Evolutions of the word Romanice were used to refer first to the Romance languages and eventually also to the works composed in them. The genre of chivalric romance initially focused on the heroic military deeds of knights, which led to the use of the word romantic in the sense of chivalrous. As the genre evolved, starting after the Renaissance and especially in the Romantic period, it focused increasingly on love in the modern sense.

The general idea of "romantic love" in the Western tradition is believed to have originated in the late nineteenth and early twentieth centuries, primarily from that of the French culture. This idea is what has spurred the connection between the words "romantic" and "lover", thus coining English phrases for romantic love such as "loving like the Romans do". The precise origins of such a connection are unknown, however. Although the word "romance" or the equivalents thereof may not have the same connotation in other cultures, the general idea of "romantic love" appears to have crossed cultures and been accepted as a concept at one point in time or another.

Courtly love
The conception of romantic love was popularized in Western culture by the concept of courtly love. Knights of the Middle Ages were thought to have engaged in non-sexual relationships with women of nobility whom they served. These relations were highly elaborate and ritualized in a complexity that was steeped in a framework of tradition, which stemmed from theories of etiquette derived out of chivalry as a moral code of conduct.

Courtly love and the notion of domnei were often the subjects of troubadours, and could be typically found in artistic endeavors such as lyrical narratives and poetic prose of the time. Since marriage was commonly a formal arrangement, courtly love sometimes permitted expressions of emotional closeness that may have been lacking from the union between husband and wife. Courtly love did not necessarily refer to those engaging in sexual acts. It may also have referred to caring and emotional intimacy. The bond between a knight and his Lady, or the woman of typically high stature of whom he served, may in some cases have been one such example.

Religious meditations upon the Virgin Mary were partially responsible for the development of chivalry as an ethic and lifestyle. A lady's honor and a knight's devotion to her, coupled with an obligatory respect for all women, factored prominently in the identity of medieval knighthood. Members of the aristocracy were schooled in the principles of chivalry, which facilitated important changes in attitudes regarding the value of women.

Modern historians such as D. W. Robertson Jr., John C. Moore, and E. Talbot Donaldson consider the concept of courtly love to be a modern invention. Donaldson called it "The Myth of Courtly Love," on the basis that it is not supported in medieval texts. Other scholars consider courtly love to have been purely a literary convention. Examples of allegorical use of the concept can be found in the Middle Ages, but there are no historical records that offer evidence of its presence in reality. Historian John Benton found no documentary evidence in law codes, court cases, chronicles or other historical documents.

Types
Romantic love is contrasted with platonic love, which in all usages precludes sexual relations, yet only in the modern usage does it take on a fully nonsexual sense, rather than the classical sense, in which sexual drives are sublimated.

Unrequited love can be romantic in different ways: comic, tragic, or in the sense that sublimation itself is comparable to romance, where the spirituality of both art and egalitarian ideals is combined with strong character and emotions. Unrequited love is typical of the period of romanticism, but the term is distinct from any romance that might arise within it.

Romantic love may also be classified according to two categories, "popular romance" and "divine or spiritual" romance:

 * Popular romance: Popular romance may include, but is not limited to the following types: idealistic, normal intense (such as the emotional aspect of "falling in love"), predictable as well as unpredictable, consuming (meaning consuming of time, energy and emotional withdrawals and bids), intense but out of control (such as the aspect of "falling out of love") material and commercial (such as societal gain mentioned in a later section of this article), physical and sexual, and finally grand and demonstrative.
 * Divine (or spiritual) romance: Divine (spiritual) romance may include, but is not limited to these following types: realistic, as well as plausible unrealistic, optimistic as well as pessimistic (depending upon the particular beliefs held by each person within the relationship.), abiding (e.g. the theory that each person had a predetermined stance as an agent of choice; such as "choosing a husband" or "choosing a soul mate".), non-abiding (e.g. the theory that each person do not choose their actions, and therefore their romantic love involvement has been drawn from sources outside of themselves), predictable as well as unpredictable, self-control (such as obedience and sacrifice within the context of the relationship) or lack thereof (such as disobedience within the context of the relationship), emotional and personal, soulful (in the theory that the mind, soul, and body, are one connected entity), intimate, and infinite (such as the idea that love itself or the love of a God's "unconditional" love is or could be everlasting).

Plato
Greek philosophers and authors have had many theories of love. Some of these theories are presented in Plato's Symposium. Six Athenian friends, including Socrates, drink wine and each give a speech praising the deity Eros. When his turn comes, Aristophanes says in his mythical speech that sexual partners seek each other because they are descended from beings with spherical torsos, two sets of human limbs, genitalia on each side, and two faces back to back. Their three forms included the three permutations of pairs of gender (i.e. one masculine and masculine, another feminine and feminine, and the third masculine and feminine) and they were split by the gods to thwart the creatures' assault on heaven, recapitulated, according to the comic playwright, in other myths such as the Aloadae.

This story is relevant to modern romance partly because of the image of reciprocity it shows between the sexes. In the final speech before Alcibiades arrives, Socrates gives his encomium of love and desire as a lack of being, namely, the being or form of beauty.

René Girard
Though there are many theories of romantic love—such as that of Robert Sternberg, in which it is merely a mean combining liking and sexual desire—the major theories involve far more insight. For most of the 20th century, Freud's theory of the family drama dominated theories of romance and sexual relationships. This gave rise to a few counter-theories. Theorists like Deleuze counter Freud and Jacques Lacan by attempting to return to a more naturalistic philosophy:

René Girard argues that romantic attraction is a product of jealousy and rivalry—particularly in a triangular form.

Girard, in any case, downplays romance's individuality in favor of jealousy and the love triangle, arguing that romantic attraction arises primarily in the observed attraction between two others. A natural objection is that this is circular reasoning, but Girard means that a small measure of attraction reaches a critical point insofar as it is caught up in mimesis. Shakespeare's plays A Midsummer Night's Dream, As You Like It, and The Winter's Tale are the best known examples of competitive-induced romance.

Girard's theory of mimetic desire is controversial because of its alleged sexism. This view has to some extent supplanted its predecessor, Freudian Oedipal theory. It may find some spurious support in the supposed attraction of women to aggressive men. As a technique of attraction, often combined with irony, it is sometimes advised that one feign toughness and disinterest, but it can be a trivial or crude idea to promulgate to men, and it is not given with much understanding of mimetic desire in mind. Instead, cultivating a spirit of self-sacrifice, coupled with an attitude of appreciation or contemplation, directed towards the other of one's attractions, constitutes the ideals of what we consider to be true romantic love. Mimesis is always the desire to possess, in renouncing it we offer ourselves as a sacrificial gift to the other.

Mimetic desire is often challenged by feminists, such as Toril Moi, who argue that it does not account for the woman as inherently desired.

Though the centrality of rivalry is not itself a cynical view, it does emphasize the mechanical in love relations. In that sense, it does resonate with capitalism and cynicism native to post-modernity. Romance in this context leans more on fashion and irony, though these were important for it in less emancipated times. Sexual revolutions have brought change to these areas. Wit or irony therefore encompass an instability of romance that is not entirely new but has a more central social role, fine-tuned to certain modern peculiarities and subversion originating in various social revolutions, culminating mostly in the 1960s.

Arthur Schopenhauer
The process of courtship also contributed to Arthur Schopenhauer's pessimism, despite his own romantic success, and he argued that to be rid of the challenge of courtship would drive people to suicide with boredom. Schopenhauer theorized that individuals seek partners looking for a "complement" or completing of themselves in a partner, as in the cliché that "opposites attract", but with the added consideration that both partners manifest this attraction for the sake of the species:

But what ultimately draws two individuals of different sex exclusively to each other with such power is the will-to-live which manifests itself in the whole species, and here anticipates, in the individual that these two can produce, an objectification of its true nature corresponding to its aims. —World as Will and Representation, Volume 2, Chapter XLIV

Other philosophers
Later modern philosophers such as La Rochefoucauld, David Hume and Jean-Jacques Rousseau also focused on morality, but desire was central to French thought and Hume himself tended to adopt a French worldview and temperament. Desire in this milieu meant a very general idea termed "the passions", and this general interest was distinct from the contemporary idea of "passionate" now equated with "romantic". Love was a central topic again in the subsequent movement of Romanticism, which focused on such things as absorption in nature and the absolute, as well as platonic and unrequited love in German philosophy and literature.

French philosopher Gilles Deleuze linked this concept of love as a lack mainly to Sigmund Freud, and Deleuze often criticized it.

American views of romantic love
Victor C. De Munck and David B. Kronenfeld conducted a study named "Romantic Love in the United States: Applying Cultural Models Theory and Methods". This study was conducted through an investigation of two cultural model cases. It states that in America, "we have a rather and dynamic cultural model that is falsifiable and predictive of successful love relationships" Which supports that is popular for American people to successfully share feelings of romanticism with each other's partners. It describes American culture by stating: "The model is unique in that it combines passion with comfort and friendship as properties of romantic love." One of its main contributions is advising the reader that "For successful romantic love relations, a person would feel excited about meeting their beloved; make passionate and intimate love as opposed to only physical love; feel comfortable with the beloved, behaving in a companionable, friendly way with one's partner; listen to the other's concerns, offering to help out in various ways if necessary; and, all the while, keeping a mental ledger of the degree to which altruism and passion are mutual."

Literature
Shakespeare and Søren Kierkegaard share a similar viewpoint that marriage and romance are not harmoniously in tune with each other. In Shakespeare's Measure for Measure, for example, "...there has not been, nor is there at this point, any display of affection between Isabella and the Duke, if by affection we mean something concerned with sexual attraction. The two at the end of the play love each other as they love virtue." In Romeo and Juliet, in saying "all combined, save what thou must combine By holy marriage", Romeo implies that it is not marriage with Juliet that he seeks but simply to be joined with her romantically.

Kierkegaard addressed these ideas in works such as Either/Or and Stages on Life's Way: "In the first place, I find it comical that all men are in love and want to be in love, and yet one never can get any illumination upon the question what the lovable, i.e., the proper object of love, really is." In his 2008 book How to Make Good Decisions and Be Right All the Time, British writer Iain King tried to establish rules for romance applicable across most cultures. He concluded on six rules, including:
 * 1) Do not flirt with someone unless you mean it.
 * 2) Do not pursue people who you are not interested in, or who are not interested in you.
 * 3) In general, express your affection or uncertainty clearly, unless there is a special reason not to.

Psychology
Many theorists attempt to analyze the process of romantic love.

Anthropologist Helen Fisher, in her book Why We Love, uses brain scans to show that love is the product of a chemical reaction in the brain. Norepinephrine and dopamine, among other brain chemicals, are responsible for excitement and bliss in humans as well as non-human animals. Fisher uses MRI to study the brain activity of a person "in love" and she concludes that love is a natural drive as powerful as hunger.

Psychologist Karen Horney in her article "The Problem of the Monogamous Ideal", indicates that the overestimation of love leads to disillusionment; the desire to possess the partner results in the partner wanting to escape; and the friction against sex result in non-fulfillment. Disillusionment plus the desire to escape plus non-fulfillment result in a secret hostility, which causes the other partner to feel alienated. Secret hostility in one and secret alienation in the other cause the partners to secretly hate each other. This secret hate often leads one or the other or both to seek love objects outside the marriage or relationship.

Psychologist Harold Bessell in his book The Love Test, reconciles the opposing forces noted by the above researchers and shows that there are two factors that determine the quality of a relationship. Bessell proposes that people are drawn together by a force he calls "romantic attraction", which is a combination of genetic and cultural factors. This force may be weak or strong and may be felt to different degrees by each of the two love partners. The other factor is "emotional maturity", which is the degree to which a person is capable of providing good treatment in a love relationship. It can thus be said that an immature person is more likely to overestimate love, become disillusioned, and have an affair whereas a mature person is more likely to see the relationship in realistic terms and act constructively to work out problems.

Romantic love, in the abstract sense of the term, is traditionally considered to involve a mix of emotional and sexual desire for another as a person. However, Lisa M. Diamond, a University of Utah psychology professor, proposes that sexual desire and romantic love are functionally independent and that romantic love is not intrinsically oriented to same-gender or other-gender partners. She also proposes that the links between love and desire are bidirectional as opposed to unilateral. Furthermore, Diamond does not state that one's sex has priority over another sex (a male or female) in romantic love because her theory suggests it is as possible for someone who is homosexual to fall in love with someone of the other gender as for someone who is heterosexual to fall in love with someone of the same gender. In her 2012 review of this topic, Diamond emphasized that what is true for men may not be true for women. According to Diamond, in most men sexual orientation is fixed and most likely innate, but in many women sexual orientation may vary from 0 to 6 on the Kinsey scale and back again.

Martie Haselton, a psychologist at UCLA, considers romantic love a "commitment device" or mechanism that encourages two humans to form a lasting bond. She has explored the evolutionary rationale that has shaped modern romantic love and has concluded that long-lasting relationships are helpful to ensure that children reach reproductive age and are fed and cared for by two parents. Haselton and her colleagues have found evidence in their experiments that suggest love's adaptation. The first part of the experiments consists of having people think about how much they love someone and then suppress thoughts of other attractive people. In the second part of the experiment the same people are asked to think about how much they sexually desire those same partners and then try to suppress thoughts about others. The results showed that love is more efficient in pushing out those rivals than sex.

Research by the University of Pavia suggests that romantic love lasts for about a year (similar to limerence) before being replaced by a more stable, non-passionate "companionate love". In companionate love, changes occur from the early stage of love to when the relationship becomes more established and romantic feelings seem to end. However, research from Stony Brook University in New York suggests that some couples keep romantic feelings alive for much longer.

Attachment patterns
Attachment styles that people develop as children can influence the way that they interact with partners in adult relationships, with secure attachment styles being associated with healthier and more trusting relationships than avoidant or anxious attachment styles. Hazen and Shaver found that adult romantic attachment styles were similar to the categories of secure, avoidant, and anxious that had previously been studied in children's attachments to their caregivers, demonstrating that attachment styles are stable across the lifespan. Later on, researchers distinguished between dismissive avoidant attachment and fearful avoidant attachment. Others have found that secure adult attachment, leading to the ability for intimacy and confidence in relationship stability, is characterized by low attachment-related anxiety and avoidance, while the fearful style is high on both dimensions, the dismissing style is low on anxiety and high on avoidance, and the preoccupied style is high on anxiety and low on avoidance.

Romantic love definition/operationalization
Irving Singer first defined love based on four Greek terms: eros, meaning the search for beauty; philia, the feelings of affection in close friendships, nomos, the submission of and obedience to higher or divine powers, and agape, the bestowal of love and affection for the divine powers. While Singer did believe that love was important to world culture, he did not believe that romantic love played a major role. However, Susan Hendrick and Clyde Hendrick at Texas Tech University have theorized that romantic love will play an increasingly important cultural role in the future, as it is considered an important part of living a fulfilling life. They also theorized that love in long-term romantic relationships has only been the product of cultural forces that came to fruition within the past 300 years. By cultural forces, they mean the increasing prevalence of individualistic ideologies, which are the result of an inward shift of many cultural worldviews.

Passionate and companionate love
Researchers have determined that romantic love is a complex emotion that can be divided into either passionate or companionate forms. Berscheid and Walster and Hatfield found that these two forms can co-exist, either simultaneously or intermittently. Passionate love is an arousal-driven emotion that often gives people extreme feelings of happiness, and can also give people feelings of anguish. Companionate love is a form that creates a steadfast bond between two people, and gives people feelings of peace. Researchers have described the stage of passionate love as "being on cocaine", since during that stage the brain releases the same neurotransmitter, dopamine, as when cocaine is being used. It is also estimated that passionate love (as with limerence) lasts for about twelve to eighteen months.

Hendrick and Hendrick studied college students who were in the early stages of a relationship and found that almost half reported that their significant other was their closest friend, providing evidence that both passionate and companionate love exist in new relationships. Conversely, in a study of long-term marriages, Contreras, Hendrick, and Hendrick found that couples endorsed measures of both companionate love and passionate love and that passionate love was the strongest predictor of marital satisfaction, showing that both types of love can endure throughout the years.

The triangular theory of love
Psychologist Robert Sternberg developed the triangular theory of love. He theorized that love is a combination of three main components: passion (physical arousal); intimacy (psychological feelings of closeness); and commitment (the sustaining of a relationship). He also theorized that the different combinations of these three components could yield up to seven different forms of love. These include popularized forms such as romantic love (intimacy and passion) and consummate love (passion, intimacy, and commitment). The other forms are liking (intimacy), companionate love (intimacy and commitment), empty love (commitment), fatuous love (passion and commitment), and infatuation (passion). Studies on Sternberg's theory love found that intimacy most strongly predicted marital satisfaction in married couples, with passion also being an important predictor (Silberman, 1995. On the other hand, Acker and Davis found that commitment was the strongest predictor of relationship satisfaction, especially for long-term relationships.

The self-expansion theory of romantic love
Researchers Arthur and Elaine Aron theorized that humans have a basic drive to expand their self-concepts. Further, their experience with Eastern concepts of love caused them to believe that positive emotions, cognitions, and relationships in romantic behaviors all drive the expansion of a person's self-concept. A study following college students for 10 weeks showed that those students who fell in love over the course of the investigation reported higher feelings of self-esteem and self-efficacy than those who did not.

Mindful relationships
Gottman studies the components of a flourishing romantic relationship have been studied in the lab Gottman & Silver, 1999. He used physiological and behavioral measures during couples' interactions to predict relationship success and found that five positive interactions to one negative interaction are needed to maintain a healthy relationship. He established a therapy intervention for couples that focused on civil forms of disapproval, a culture of appreciation, acceptance of responsibility for problems, and self-soothing.

Relationship behaviors
Recent research suggests that romantic relationships impact daily behaviors and people are influenced by the eating habits of their romantic partners. Specifically, in the early stages of romantic relationships, women are more likely to be influenced by the eating patterns (i.e., healthiness/unhealthiness) of men. However, when romantic relationships are established, men are influenced by the eating patterns of women.

Relationship maintenance
Daniel Canary from the International Encyclopedia of Marriage describes relationship maintenance as "At the most basic level, relational maintenance refers to a variety of behaviors used by partners in an effort to stay together." Maintaining stability and quality in a relationship is the key to success in a romantic relationship. He says that: "simply staying together is not sufficient; instead, the quality of the relationship is important. For researchers, this means examining behaviors that are linked to relational satisfaction and other indicators of quality." Canary suggests using the work of John Gottman, an American physiologist best known for his research on marital stability for over four decades, serves as a guide for predicting outcomes in relationships because "Gottman emphasizes behaviors that determine whether or not a couple gets divorced".

Furthermore, Canary also uses the source from Stafford and Canary, a journal on Communication Monographs, because they created five great strategies based on maintaining quality in a relationship, the article's strategies are to provide:
 * Positivity: being joyful and optimistic, not criticizing each other.
 * Assurances: proving one's commitment and love.
 * Openness: to be honest with one another according to what they want in the relationship.
 * Social networks: efforts into involving friends and family in their activities.
 * Sharing tasks: complementing each other's needs based on daily work.

On relational maintenance, Steven McCornack and Joseph Ortiz, the authors of the book Choices & Connection, state that relationship maintenance "refers to the use of communication behaviors to keep a relationship strong and to ensure that each party continues to draw satisfaction from the relationship".

Physiology
Researchers such as Feeney and Noller question the stability of attachment style across the life span since studies that measured attachment styles at time points ranging from two weeks to eight months found that one out of four adults' attachment style changed. Furthermore, a study by Lopez and Gormley found that attachment styles could change during the first year of college and that changes to more secure attachment styles were associated with adjustments in self-confidence ratings and coping styles. On the other hand, attachment styles in childhood mirror the ones found in adult romantic relationships. In addition, research has shown that building interpersonal connections strengthens neural regulatory systems that are involved in emotions of empathy, enjoyment of positive social events, and stress management, providing evidence that early social interactions affect adult relationships.

Another topic of controversy in the field of romantic relationships is that of domestic abuse. Following the theory that romantic love evolved as a byproduct of survival, it can be said that in some instances, it has turned into a maladaptation. Oxytocin (OT) is a neurophysical hormone produced in the brain. It is known to cause a decrease in stress response. It also can cause an increase in feelings of attachment. In the beginning stages of a romantic relationship, OT levels surge and then remain relatively stable over the duration of the relationship. The higher the surge of OT, the greater the likelihood is of partners staying together. It plays an important role in increasing positive interpersonal behaviors such as trust, altruism, empathy, etc. This response is not universal and can in fact, cause the opposite to occur depending on environment and individual. Individuals ranked high in rejection sensitivity exhibited aggressive tendencies and decreased willingness for cooperation, indicating a link between oxytocin and relationship maintenance.

The feelings associated with romantic love function to ensure the greater reproductive fitness of individuals. The obligations of individuals in romantic relationships to preserve these bonds are based in kin selection theory, where by exhibiting aggressive behavior, a mate can use intimidation and dominance to ward off other potential predators, thus protecting the pair bond and their actual or potential offspring. This has however evolved to the point where it has become detrimental to the fitness of individuals; what is causing attachment to occur in a relationship, is now causing one partner to harm the other.

In the search for the root of intimate partner violence (IPV), intranasal oxytocin was administered to a control group and a group of participants with aggressive tendencies. Participants were then surveyed on how willing they were to engage in five behaviors towards their romantic partner. What they found was that oxytocin increased IPV inclinations only among the participants with a predisposition towards aggressive tendencies.

title: Romance (love)


text:
NYS

NYS may refer to:

 * New York Skyports Seaplane Base (IATA: NYS)
 * National Youth Service, of several countries
 * New York State
 * New York Shipbuilding, a corporation
 * Nyungar language (ISO 639-3: nys), an Australian Aboriginal language or dialect continuum

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: NYS


text:
Transpower New Zealand

Transpower New Zealand Limited (TPNZ) is the state-owned enterprise responsible for electric power transmission in New Zealand. It performs two major functions in the New Zealand electricity market. As the owner of the National Grid it provides the infrastructure of electric power transmission that allows consumers to have access to generation from a wide range of sources, and enables competition in the wholesale electricity market; as system operator it manages the real-time operation of the grid and the physical operation of the electricity market.

Transpower was initially formed as an operating division of the Electricity Corporation of New Zealand (ECNZ) in 1987. In 1994 it was separated from ECNZ and corporatised to become a state-owned enterprise with its own board of directors and ministerial shareholders, the Minister of Finance and the Minister of State-Owned Enterprises. The New Zealand Treasury's Commercial Operations group (formerly the Crown Ownership Monitoring Unit) monitors the performance of Transpower on behalf of the shareholding ministers.

Role of the National Grid
The New Zealand national grid provides the means of transporting bulk electricity from where it is generated (by companies like Meridian Energy and Mercury Energy) to cities, towns and some major industrial users like the Tiwai Point Aluminium Smelter. Most of the electricity from the national grid is delivered to New Zealand's homes and businesses by electricity distribution companies like Vector and Orion. A few large industrial users are directly connected to the national grid.

Transpower owns and operates 11806 km of transmission lines. A core network consisting of 5719 km (route) of 220 kV transmission lines exist in each island (one line is built to 400 kV but operates at 220 kV), and this is supplemented by 4719 km of 110 kV transmission lines and 797 km of 66 kV and 50 kV transmission lines, which interconnect the core grid to smaller load centres and power stations. Transpower also owns and operates the HVDC Inter-Island, a 611 km ±350 kV high-voltage direct current link between the two islands. There are 178 electrical substations, containing 1116 transformers with a total capacity of 14,500 MVA.

Regulation under the Commerce Act
The revenue that Transpower receives for the provision of the transmission service is regulated by the Commerce Commission, under Part IV of the Commerce Act. The type of regulation is individual price-quality path (IPP) regulation, and came into effect on 1 April 2011. The individual price-quality path governs Transpower's revenues for each pricing year, with the paths being reset either every four or five years. Quality targets for the transmission service are also reviewed and monitored in the regulatory process.

Role of the system operator
The role of the system operator is to manage the security of the power system in real time and co-ordinate the supply of and demand for electricity, in a manner that avoids fluctuations in frequency or interruptions of supply. The system operator is required to maintain a continuous (second-by-second) balance between electricity supply from power stations and demand from consumers, and also ensure the provision of reserves that will allow for sudden contingencies. The system operator achieves this by determining the optimal combination of generating stations and reserve providers for each market trading period, instructing generators when and how much electricity to generate, and managing any contingent events that cause the balance between supply and demand to be disrupted. System operations staff undertake this work using sophisticated energy modelling and communications systems. In addition to its roles of real-time dispatch of generation and managing security, the system operator also carries out investigations and planning to ensure that supply can meet demand and system security can be maintained during future trading periods. Examples of planning work may include co-ordinating generator and transmission outages, facilitating commissioning of new generating plant and procuring ancillary services to support power system operation.

The system operator service is provided and funded under an agreement with the Electricity Authority.

title: Transpower New Zealand


text:
Meridian Energy

Meridian Energy Limited is a New Zealand electricity generator and retailer. The company generates the largest proportion of New Zealand's electricity, generating 35 percent of the country's electricity in the year ending December 2014, and is the fourth largest retailer, with 14 percent of market share in terms of customers as of December 2015.

Meridian was one of three electricity companies formed from the break-up of the Electricity Corporation of New Zealand (ECNZ) in 1998–99, taking over the Waitaki River and the Manapouri hydro schemes. Originally a state-owned enterprise wholly owned by the New Zealand Government, the company was partially privatised in October 2013 by the Fifth National Government, with the government retaining a 51.02% shareholding.

Today, Meridian operates seven hydroelectric power stations and one wind farm in the South Island of New Zealand, and four wind farms in the North Island.

History
Meridian originated from the break-up of the Electricity Corporation of New Zealand (ECNZ) in 1999 as a result of the reforms of the New Zealand Electricity Market. Meridian's share of ECNZ was corporatised as a state-owned enterprise with its own board of directors and with two Ministerial shareholders: the Minister of Finance and the Minister of State-Owned Enterprises. In 2013 it was partially privatised by the fifth National Government of New Zealand.

As part of reforms, local electricity companies were split into lines and retail and the retail portion sold off. Meridian initially acquired the retail base of Northpower, Centralines, Scanpower, and Network Waitaki, and later acquired Orion's retail base from NGC.

 * 2001 – Meridian purchased five mini hydro-power stations in Australia. These stations linked with dams used primarily for irrigation, and have a total generating capacity of 62 MW.
 * September 2001 – Meridian purchased the South Island customer-base of Natural Gas Corporation (NGC), at the time New Zealand's largest electricity retailer. The purchase came towards the end of an exceptionally dry autumn. Low hydro-levels had driven the wholesale market spot prices to very high levels. NGC had purchased the customer-base when Canada's TransAlta quit New Zealand. NGC re-branded itself as OnEnergy to escape the poor reputation of the "TransAlta" brand. OnEnergy found itself with insufficient generation capacity to stand the high winter market prices and had made the critical mistake of not purchasing any hedge contracts. It attempted to raise its retail prices, but its customers then flocked to other retailers. Finally, after suffering huge losses, NGC had perforce to quit the retail sector, selling its customer-base to two of the Government's companies: Meridian and Genesis Energy. At that point, the New Zealand electricity market became further vertically integrated, and many have come to believe that this adversely affected competition in the retail electricity market.
 * April 2003 – Meridian extended its operations in Australia with the purchase of Southern Hydro, increasing its Australian generating capacity by 540 MW.
 * Southern Hemisphere Winter 2003 – Low hydro inflows and storage levels again resulted in exceptional wholesale market spot prices. As a consequence, the retailers TrustPower and Freshstart abandoned market areas where they had no generation. This strengthened Meridian's dominance of the South Island customer-base.
 * 29 March 2004 – Meridian cancelled Project Aqua, a controversial 524 MW power scheme for six dams and a man-made canal on the Lower Waitaki River in North Otago. The scheme allegedly represented the last opportunity for large-scale hydroelectric development of this magnitude in New Zealand. Abandoning the venture cost Meridian NZ$38.7 million. – Meridian stopped the scheme because of uncertainty over rights to use the water, growing costs, and the difficulties and uncertainties with obtaining consents under the Resource Management Act legislation. In July 2004, Meridian announced an independent audit of the abandoned scheme.
 * 9 December 2004 – then Prime Minister Helen Clark officially opened the Te Āpiti Wind Farm – Meridian's first wind farm.
 * 2 June 2005 – Meridian announced a proposal to develop a wind farm west of Wellington, Project West Wind with up to 70 wind turbines with a total capacity of 210 MW, built across 55.8 square km on rural land near Mākara at the south-western tip of the North Island. A local pressure group, the Makara Guardians, opposed the scheme. Successful application for resource consent for the project was announced on 21 December 2005. The consent was subsequently appealed and upheld in May 2007.
 * 30 November 2005 – Meridian completed the sale of its Australian operation, Southern Hydro, for A$1.42 billion (NZ$1.52 billion) to Australian Gas Light Company. Meridian had steadily expanded and upgraded its assets in Australia since purchase, including commissioning a 91 MW wind-farm. The sale commanded a hefty premium, driven by new demand for renewable energy-generation because of mandatory Australian requirements that electricity retailers sell a proportion of renewable energy.
 * 8 June 2007 – The White Hill Wind Farm is officially opened.
 * 29 April 2009 – Prime Minister John Key officially turns on the first 15 turbines on the West Wind wind farm.
 * 1 June 2011 – The sale of Meridian Energy's Tekapo A and Tekapo B hydroelectric power stations to Genesis Energy took effect. The sale was part of a package of government reforms aimed at improving the electricity sector.

 * 30 September 2013 – 49 percent of shares in the company officially offered for sale at between $1.50 and $1.80

Power stations
Meridian Energy owns and operates seven hydroelectric power stations in the South Island – six on the Waitaki River and at Manapouri. It also owns and operates five wind farms in New Zealand, and a single turbine in Brooklyn, Wellington. In total, Meridian has a total installed capacity of 2,754 MW in New Zealand and 201 MW overseas.

Proposed
Projects being developed by Meridian Energy include the following.

Carbon Footprint
In 2006, Greenpeace judged Meridian as the only "green" electricity company in New Zealand. In 2007, Meridian announced that it had received CarboNZero certification from Landcare Research confirming that the generation and retailing of its electricity was carbon neutral.

In 2008, Meridian issued and sold the first carbon credits issued and sold under the JI program of the Kyoto Protocol.

In June 2008, National's Climate Change spokesman Nick Smith complained to the Commerce Commission that Meridian's claim of carbon neutrality in its advertising was misleading as Smith considered that Meridian had to buy thermally generated power during dry years to supply its customers. A spokesman for Meridian said they stood by the validity of the certification of their carbon-neutral status. In July 2009, the Commerce Commission concluded that Meridian's statements of carbon neutrality were not misleading.

Electric Vehicles and Charging Programme
In 2015 Meridian began converting its business fleet to electric vehicles in an effort to reduce carbon emissions. In early 2019 Meridian joined the EV100 initiative, it has committed to its light passenger vehicle business fleet becoming 100% electric by 2030. In August 2019 the company won the Deloitte Energy Award for a Low Carbon Initiative for its work on electric business fleet conversion.

Kākāpō Recovery Programme
Meridian Energy are National Partners of the Department of Conservation Kākāpō Recovery Programme since 2016. Kākāpō are an endangered New Zealand native parrot. The involvement helps fund research and initiatives relating to genetics, nutrition, disease management and finding new sites. Meridian staff are also involved through providing electrical support and volunteers to the remote pest-free islands the kākāpō are surviving on.

Project River Recovery
In 1990 Meridian established Project River Recovery, recognising the impacts of hydroelectric development from the 1930s to the 1980s on the Waitaki's braided rivers and wetlands. Project River Recovery's work is run by the New Zealand Department of Conservation and includes intensive weed control, predator control, construction of wetlands, and research and monitoring programmes. When Tekapo A and Tekapo B were sold to Genesis Energy in 2011, the electricity company joined the compensatory funding agreement.

Waiau River Recovery
In 1996 the Waiau Fisheries and Wildlife Enhancement Trust was formed to mitigate and improve the Waiau River from impacts by the Manapouri Hydro Station. The trust was established in partnership with the Waiau Working Party and ECNZ (now Meridian Energy Limited). The area covered is from Te Wae Wae Bay in the south to Lake Te Anau in the north. The work focuses on enhancing wetlands, waterways and riparian plantings.

Wellington Wind Sculpture Walkway
Wellington, New Zealand's capital city, is well known for wind and the Meridian Energy Wind Sculpture walkway celebrates this. In 2007 the four sculptures won Best Public Art and the final piece was opened in May 2010. The five sculptures are the ' Zephyrometer'  by Phil Price, ' Urban Forest'  by Leon van den Eijkel (in collaboration with Allan Brown), ' Akau Tangi'  by Phil Dadson, ' Tower of Light ' by Andrew Drummond and 'Pacific Grass ' by Kon Dimopoulos. The sculptures are managed by the Wellington Sculpture Trust

KidsCan
In 2013 Meridian became the principle partner of the KidsCan Charity. In April 2019 the company committed to a further three years of support, helping provide lunches, raincoats, shoes and warm clothing to kids in need.

Power Up Community Fund
Meridian supports communities near its generation assets through the Power Up fund. This includes promoting conservation, community and educational efforts in seven communities around New Zealand.

Controversy
In 2019, Meridian was found to mislead consumers when they implied the electricity they retailed was 100% renewable after a complaint was brought to the Advertising Standards Authority by rival retailer Electric Kiwi. Additionally, Meridian Energy was found to have pushed up power prices in December 2019 by unnecessarily spilling water from its South Island dams that could have been used for generation, according to a preliminary ruling from New Zealand's Electricity Authority.

Subsidiaries

 * Dam Safety Intelligence Limited, a consultancy specialising in dam safety
 * Powershop, an electricity retail broker.
 * Flux Federation, an energy software platform.
 * Arc Innovations (until 2014), a company specialising in electricity smart meters

title: Meridian Energy


text:
Pineal gland

The pineal gland (also known as the pineal body or epiphysis cerebri) is a small endocrine gland in the brain of most vertebrates. It produces melatonin, a serotonin-derived hormone, which modulates sleep patterns following the diurnal cycles. The shape of the gland resembles a pine cone, which gives it its name. The pineal gland is located in the epithalamus, near the center of the brain, between the two hemispheres, tucked in a groove where the two halves of the thalamus join. It is one of the neuroendocrine secretory circumventricular organs in which capillaries are mostly permeable to solutes in the blood.

The pineal gland is present in almost all vertebrates, but is absent in protochordates in which there is a simple pineal homologue. The hagfish, considered as a primitive vertebrate, has a rudimentary structure regarded as the "pineal equivalent" in the dorsal diencephalon. In some species of amphibians and reptiles, the gland is linked to a light-sensing organ, variously called the parietal eye, the pineal eye or the third eye. Reconstruction of the biological evolution pattern suggests that the pineal gland was originally a kind of atrophied photoreceptor that developed into a neuroendocrine organ.

Ancient Greeks were the first to notice the pineal gland and believed it to be a valve, a guardian for the flow of pneuma. Galen in the 2nd century C.E. could not find any functional role and regarded the gland as a structural support for the brain tissue. He gave the name konario, meaning cone or pinecone, which during Renaissance was translated to Latin as pinealis. The 17th century philosopher René Descartes regarded the gland as having a mystical purpose, describing it as the "principal seat of the soul". In the mid-20th century, the real biological role as a neuroendocrine organ was established.

Etymology
The word pineal, from Latin pinea (pine-cone) in reference to the gland's similar shape, was first used in the late 17th century.

Structure
The pineal gland is a pine cone-shaped (hence the name), unpaired midline brain structure. It is reddish-gray in colour and about the size of a grain of rice (5–8 mm) in humans. It forms part of the epithalamus. It is attached to the rest of the brain by a pineal stalk. The ventral lamina of the pineal stalk is continuous with the posterior commissure, and its dorsal lamina with the habenular commissure.

Location
It normally lies in a depression between the two superior colliculi. It is situated between the laterally positioned thalamic bodies, and posterior to the habenular commissure. It is located in the quadrigeminal cistern. It is located posterior to the third ventricle and encloses the small, cerebrospinal fluid-filled pineal recess of the third ventricle which projects into the stalk of the gland.

Blood supply
Unlike most of the mammalian brain, the pineal gland is not isolated from the body by the blood–brain barrier system; it has profuse blood flow, second only to the kidney, supplied from the choroidal branches of the posterior cerebral artery.

Afferents
The afferent nerve suppy of pineal gland is by the nervus conarii which receives postganglionic sympathetic afferents from the superior cervical ganglion, and parasympathetic afferents from the pterygopalatine ganglia and otic ganglia. According to research on animals, neurons of the trigeminal ganglion that are involved in pituitary adenylate cyclase-activating peptide neuropeptide signaling project the gland.

Neural pathway for melatonin production
The canonical neural pathway regulating pineal melatonin production begins in the eye with the intrinsically photosensitive ganglion cells of the retina which project inhibitory GABAergic efferents to the paraventricular nucleus of hypothalamus via the retinohypothalamic tract. The paraventricular nucleus in turn projects to the superior cervical ganglia, which finally projects to the pineal gland. Darkness thus leads to disinhibition of the paraventricular nucleus, leading it to activate pineal gland melatonin production by way of the superior cervical ganglia.

Microanatomy
The pineal body in humans consists of a lobular parenchyma of pinealocytes surrounded by connective tissue spaces. The gland's surface is covered by a pial capsule.

The pineal gland consists mainly of pinealocytes, but four other cell types have been identified. As it is quite cellular (in relation to the cortex and white matter), it may be mistaken for a neoplasm.

Development
The human pineal gland grows in size until about 1–2 years of age, remaining stable thereafter, although its weight increases gradually from puberty onwards. The abundant melatonin levels in children are believed to inhibit sexual development, and pineal tumors have been linked with precocious puberty. When puberty arrives, melatonin production is reduced.

Symmetry
In the zebrafish the pineal gland does not straddle the midline, but shows a left-sided bias. In humans, functional cerebral dominance is accompanied by subtle anatomical asymmetry.

Function
One function of the pineal gland is to produce melatonin. Melatonin has various functions in the central nervous system, the most important of which is to help modulate sleep patterns. Melatonin production is stimulated by darkness and inhibited by light. Light sensitive nerve cells in the retina detect light and send this signal to the suprachiasmatic nucleus (SCN), synchronizing the SCN to the day-night cycle. Nerve fibers then relay the daylight information from the SCN to the paraventricular nuclei (PVN), then to the spinal cord and via the sympathetic system to superior cervical ganglia (SCG), and from there into the pineal gland.

The compound pinoline is also claimed to be produced in the pineal gland; it is one of the beta-carbolines. This claim is subject to some controversy.

Regulation of the pituitary gland
Studies on rodents suggest that the pineal gland influences the pituitary gland's secretion of the sex hormones, follicle-stimulating hormone (FSH), and luteinizing hormone (LH). Pinealectomy performed on rodents produced no change in pituitary weight, but caused an increase in the concentration of FSH and LH within the gland. Administration of melatonin did not return the concentrations of FSH to normal levels, suggesting that the pineal gland influences pituitary gland secretion of FSH and LH through an undescribed transmitting molecule.

The pineal gland contains receptors for the regulatory neuropeptide, endothelin-1, which, when injected in picomolar quantities into the lateral cerebral ventricle, causes a calcium-mediated increase in pineal glucose metabolism.

Regulation of bone metabolism
Studies in mice suggest that the pineal-derived melatonin regulates new bone deposition. Pineal-derived melatonin mediates its action on the bone cells through MT2 receptors. This pathway could be a potential new target for osteoporosis treatment as the study shows the curative effect of oral melatonin treatment in a postmenopausal osteoporosis mouse model.

Calcification
Calcification of the pineal gland is typical in young adults, and has been observed in children as young as two years of age. The internal secretions of the pineal gland are known to inhibit the development of the reproductive glands because when it is severely damaged in children, development of the sexual organs and the skeleton are accelerated. Pineal gland calcification is detrimental to its ability to synthesize melatonin and scientific literature presents inconclusive findings on whether it causes sleep problems.

The calcified gland is often seen in skull X-rays. Calcification rates vary widely by country and correlate with an increase in age, with calcification occurring in an estimated 40% of Americans by age seventeen. Calcification of the pineal gland is associated with corpora arenacea, also known as "brain sand".

Tumors
Tumors of the pineal gland are called pinealomas. These tumors are rare and 50% to 70% are germinomas that arise from sequestered embryonic germ cells. Histologically they are similar to testicular seminomas and ovarian dysgerminomas.

A pineal tumor can compress the superior colliculi and pretectal area of the dorsal midbrain, producing Parinaud's syndrome. Pineal tumors also can cause compression of the cerebral aqueduct, resulting in a noncommunicating hydrocephalus. Other manifestations are the consequence of their pressure effects and consist of visual disturbances, headache, mental deterioration, and sometimes dementia-like behaviour.

These neoplasms are divided into three categories: pineoblastomas, pineocytomas, and mixed tumors, based on their level of differentiation, which, in turn, correlates with their neoplastic aggressiveness. The clinical course of patients with pineocytomas is prolonged, averaging up to several years. The position of these tumors makes them difficult to remove surgically.

Other conditions
The morphology of the pineal gland differs markedly in different pathological conditions. For instance, it is known that its volume is reduced both in obese patients as well as patients with primary insomnia.

Other animals
Nearly all vertebrate species possess a pineal gland. The most important exception is a primitive vertebrate, the hagfish. Even in the hagfish, however, there may be a "pineal equivalent" structure in the dorsal diencephalon. A few more complex vertebrates have lost pineal glands over the course of their evolution. The lamprey (another primitive vertebrate), however, does possess one. The lancelet Branchiostoma lanceolatum, an early chordate which is a close relative to vertebrates, also lacks a recognizable pineal gland. Protochordates in general do not have the distinct structure as an organ, but they have a mass of photoreceptor cells called lamellar body, which is regarded as a pineal homologue.

The results of various scientific research in evolutionary biology, comparative neuroanatomy and neurophysiology have explained the evolutionary history (phylogeny) of the pineal gland in different vertebrate species. From the point of view of biological evolution, the pineal gland is a kind of atrophied photoreceptor. In the epithalamus of some species of amphibians and reptiles, it is linked to a light-sensing organ, known as the parietal eye, which is also called the pineal eye or third eye. It is likely that the common ancestor of all vertebrates had a pair of photosensory organs on the top of its head, similar to the arrangement in modern lampreys. In many lower vertebrates (such as species of fish, amphibians and lizards), the pineal gland is associated with parietal or pineal eye. In these animals, the parietal eye acts as a photoreceptor, and hence are also known as the third eye, and they can be seen on top of the head in some species. Some extinct Devonian fishes have two parietal foramina in their skulls, suggesting an ancestral bilaterality of parietal eyes. The parietal eye and the pineal gland of living tetrapods are probably the descendants of the left and right parts of this organ, respectively.

During embryonic development, the parietal eye and the pineal organ of modern lizards and tuataras form together from a pocket formed in the brain ectoderm. The loss of parietal eyes in many living tetrapods is supported by developmental formation of a paired structure that subsequently fuses into a single pineal gland in developing embryos of turtles, snakes, birds, and mammals.

The pineal organs of mammals fall into one of three categories based on shape. Rodents have more structurally complex pineal glands than other mammals.

Crocodilians and some tropical lineages of mammals (some xenarthrans (sloths), pangolins, sirenians (manatees and dugongs), and some marsupials (sugar gliders)) have lost both their parietal eye and their pineal organ. Polar mammals, such as walruses and some seals, possess unusually large pineal glands.

All amphibians have a pineal organ, but some frogs and toads also have what is called a "frontal organ", which is essentially a parietal eye.

Pinealocytes in many non-mammalian vertebrates have a strong resemblance to the photoreceptor cells of the eye. Evidence from morphology and developmental biology suggests that pineal cells possess a common evolutionary ancestor with retinal cells.

Pineal cytostructure seems to have evolutionary similarities to the retinal cells of the lateral eyes. Modern birds and reptiles express the phototransducing pigment melanopsin in the pineal gland. Avian pineal glands are thought to act like the suprachiasmatic nucleus in mammals. The structure of the pineal eye in modern lizards and tuatara is analogous to the cornea, lens, and retina of the lateral eyes of vertebrates.

In most vertebrates, exposure to light sets off a chain reaction of enzymatic events within the pineal gland that regulates circadian rhythms. In humans and other mammals, the light signals necessary to set circadian rhythms are sent from the eye through the retinohypothalamic system to the suprachiasmatic nuclei (SCN) and the pineal gland.

The fossilized skulls of many extinct vertebrates have a pineal foramen (opening), which in some cases is larger than that of any living vertebrate. Although fossils seldom preserve deep-brain soft anatomy, the brain of the Russian fossil bird Cerebavis cenomanica from Melovatka, about 90 million years old, shows a relatively large parietal eye and pineal gland.

History
The secretory activity of the pineal gland is only partially understood. Its location deep in the brain suggested to philosophers throughout history that it possessed particular importance. This combination led to its being regarded as a "mystery" gland with mystical, metaphysical, and occult theories surrounding its perceived functions. The earliest recorded description of the pineal gland is from the Greek physician Galen in the 2nd century C.E. According to Galen, Herophilus (325–280 B.C.E.) had already considered the structure as a kind of valve that partitioned the brain chambers, particularly for the flow of vital spirits (pneuma). Specifically, the ancient Greeks believed that the structure maintained the movement of vital spirits from the middle (now identified as the third) ventricle to the one in the parencephalis (fourth ventricle).

Galen described the pineal gland in De usu partium corporis humani, libri VII (On the Usefulness of Parts of the Body, Part 8) and De anatomicis administrationibus, libri IX (On Anatomical Procedures, Part 9). He introduced the name κωνάριο (konario, often Latinised as conarium) that means cone, as in pinecone, in De usu partium corporis humani. He correctly located the gland as directly lying behind the third ventricle. He argued against the prevailing concept of it as a valve for two basic reasons: it is located outside of the brain tissue and it does not move on its own.

Galen instead identified the valve as a worm-like structure in the cerebellum (later called vermiform epiphysis, known today as the vermis cerebelli or cerebellar vermis). From his study on the blood vessels surrounding the pineal gland he discovered the great vein of the cerebellum, later called the vein of Galen. He could not establish any functional role of the pineal gland and regarded it as a structural support for the cerebral veins.

Seventeenth-century philosopher and scientist René Descartes discussed the pineal gland both in his first book, the Treatise of Man (written before 1637, but only published posthumously 1662/1664), and in his last book, The Passions of the Soul (1649) and he regarded it as "the principal seat of the soul and the place in which all our thoughts are formed". In the Treatise of Man, he described conceptual models of man, namely creatures created by God, which consist of two ingredients, a body and a soul. In the Passions, he split man up into a body and a soul and emphasized that the soul is joined to the whole body by "a certain very small gland situated in the middle of the brain's substance and suspended above the passage through which the spirits in the brain's anterior cavities communicate with those in its posterior cavities". Descartes gave importance to the structure as it was the only unpaired component of the brain.

The Latin name pinealis became popular in the 17th century. For example, English physician Thomas Willis described a glandula pinealis in his book, Cerebri anatome cui accessit nervorum descriptio et usus (1664). Willis criticised Descartes' concept, remarking: "we can scarce[ly] believe this to be the seat of the Soul, or its chief Faculties to arise from it; because Animals, which seem to be almost quite destitute of Imagination, Memory, and other superior Powers of the Soul, have this Glandula or Kernel large and fair enough."

Walter Baldwin Spencer at the University of Oxford gave the first description of the pineal gland in lizards. In 1886, he described an eye-like structure, which he called the pineal eye or parietal eye, that was associated with the parietal foramen and the pineal stalk. The presence of a pineal body was already discovered by German zoologist Franz Leydig in 1872, in European lizards. Leydig called them the "frontal organ" (German stirnorgan). In 1918, Swedish zoologist Nils Holmgren described the "parietal eye" in frogs and dogfish. He discovered that the parietal eyes were made up of sensory cells similar to the cone cells of the retina, and suggested that it was a primitive light-sensor organ (photoreceptor).

The pineal gland was originally believed to be a "vestigial remnant" of a larger organ. In 1917, it was known that extract of cow pineals lightened frog skin. Dermatology professor Aaron B. Lerner and colleagues at Yale University, hoping that a hormone from the pineal gland might be useful in treating skin diseases, isolated it and named it melatonin in 1958. The substance did not prove to be helpful as intended, but its discovery helped solve several mysteries, such as why removing a rat's pineal gland accelerated its ovary growth, why keeping rats in constant light decreased the weight of their pineals, and why pinealectomy and constant light affect ovary growth to an equal extent; this knowledge gave a boost to the then-new field of chronobiology. Of the endocrine organs, the function of the pineal gland was the last to be discovered.

Society and culture
The notion of a "pineal-eye" is central to the philosophy of the French writer Georges Bataille, which is analyzed at length by literary scholar Denis Hollier in his study Against Architecture. In this work Hollier discusses how Bataille uses the concept of a "pineal-eye" as a reference to a blind-spot in Western rationality, and an organ of excess and delirium. This conceptual device is explicit in his surrealist texts, The Jesuve and The Pineal Eye.

In the late 19th century Madame Blavatsky, founder of theosophy, identified the pineal gland with the Hindu concept of the third eye, or the Ajna chakra. This association is still popular today. The pineal gland has also featured in other religious contexts, such as in the Principia Discordia, which claims it can be used to contact the goddess of discord Eris.

In the short story "From Beyond" by H. P. Lovecraft, a scientist creates an electronic device that emits a resonance wave, which stimulates an affected person's pineal gland, thereby allowing them to perceive planes of existence outside the scope of accepted reality, a translucent, alien environment that overlaps our own recognized reality. It was adapted as a film of the same name in 1986. The 2013 horror film Banshee Chapter is heavily influenced by this short story. In Season 16, episode 6 of "American Dad" Steve tries to "astral project" using his pineal gland to help him understand the meaning of life. The episode is entitled "The Wondercabinet".

Additional images
The pineal body is labeled in these images.

title: Pineal gland


text:
España (disambiguation)

España—endogenously—is Spain, a country in southwestern Europe.

España may also refer to:

Arts and entertainment

 * España (Chabrier), an 1883 orchestral piece
 * España, a derivative 1886 waltz by Émile Waldteufel
 * España 1936, a Spanish documentary film

Places

 * España Lake, Bolivia
 * España Boulevard, Philippines
 * España railway station, Philippines
 * España, a light rail station in Guadalajara, Mexico

Political parties

 * España 2000, Spain

Ships

 * España-class battleships of the Spanish Navy
 * SPANISH BATTLESHIP España (1913–1923)
 * SPANISH BATTLESHIP Alfonso XIII (later España, 1915–1937)

Sports teams

 * Real C.D. España, Honduras
 * España F.C., El Salvador
 * Club España, United States

title: España (disambiguation)


text:
Dummy variable (statistics)

In regression analysis, a dummy variable (also known as indicator variable or just dummy) is one that takes a binary value (0 or 1) to indicate the absence or presence of some categorical effect that may be expected to shift the outcome. For example, if we were studying the relationship between biological sex and income, we could use a dummy variable to represent the sex of each individual in the study. The variable could take on a value of 1 for males and 0 for females (or vice versa). In machine learning this is known as one-hot encoding.

Dummy variables are commonly used in regression analysis to represent categorical variables that have more than two levels, such as education level or occupation. In this case, multiple dummy variables would be created to represent each level of the variable, and only one dummy variable would take on a value of 1 for each observation. Dummy variables are useful because they allow us to include categorical variables in our analysis, which would otherwise be difficult to include due to their non-numeric nature. They can also help us to control for confounding factors and improve the validity of our results.

As with any addition of variables to a model, the addition of dummy variables will increase the within-sample model fit (coefficient of determination), but at a cost of fewer degrees of freedom and loss of generality of the model (out of sample model fit). Too many dummy variables result in a model that does not provide any general conclusions.

Dummy variables are useful in various cases. For example, in econometric time series analysis, dummy variables may be used to indicate the occurrence of wars, or major strikes. It could thus be thought of as a Boolean, i.e., a truth value represented as the numerical value 0 or 1 (as is sometimes done in computer programming).

Dummy variables may be extended to more complex cases. For example, seasonal effects may be captured by creating dummy variables for each of the seasons: D1=1 if the observation is for summer, and equals zero otherwise; D2=1 if and only if autumn, otherwise equals zero; D3=1 if and only if winter, otherwise equals zero; and D4=1 if and only if spring, otherwise equals zero. In the panel data fixed effects estimator dummies are created for each of the units in cross-sectional data (e.g. firms or countries) or periods in a pooled time-series. However in such regressions either the constant term has to be removed, or one of the dummies removed making this the base category against which the others are assessed, for the following reason:

If dummy variables for all categories were included, their sum would equal 1 for all observations, which is identical to and hence perfectly correlated with the vector-of-ones variable whose coefficient is the constant term; if the vector-of-ones variable were also present, this would result in perfect multicollinearity, so that the matrix inversion in the estimation algorithm would be impossible. This is referred to as the dummy variable trap.

title: Dummy variable (statistics)