Ganga and Jamuna Mondal (born Ayara and Jayara Ratun, 1969 or 1970), known professionally as The Spider Girls and The Spider Sisters, are conjoined twins from a Bengali family in Basirhat, West Bengal, India.

Millie McCoy and Christine McCoy (July 11, 1851 – October 8, 1912) were American conjoined twins who went by the stage names "The Carolina Twins", "The Two-Headed Nightingale" and "The Eighth Wonder of the World". The Twins traveled throughout the world performing song and dance for entertainment.

For every 200,000 live births, conjoined twins are born. Conjoined twins are identical and of the same sex one hundred percent of the time and are more common in females than in males. For surgical separations the survival rate of at least one twin surviving is approximately 75%.

Kendra Deene Herrin and Maliyah Mae Herrin (born February 26, 2002). are former conjoined twins. They were separated in August 2006. They were the first set of conjoined twins to be separated to share a kidney. Kendra retained their shared kidney following the separation surgery, while Maliyah Herrin underwent dialysis until she was transplanted with a kidney donated by her mother in April 2007.

Prior to the separation surgery, medical ethicists in the United States and in Europe discussed whether it was ethical to separate the twins because of the additional risk to Maliyah. Their family and doctors believed separation surgery would give both girls their best chance to live a normal life.

They work at the travelling "Dreamland Circus" in India. Their "act" consists of them sitting on a charpoy in a tent, with paying spectators allowed entry to view and converse with them. In 2009, they were reported to have earned GBP26 for five hours a night. They are married to a single man named Gadadhar, a carnival worker.

Krista and Tatiana Hogan (born October 25, 2006) are Canadians who are conjoined craniopagus twins. They are joined at the head (the top, back, and sides). They were born in Vancouver, British Columbia and are the only unseparated ones of that type currently alive in Canada. They live with their mother, Felicia Simms, in Vernon, British Columbia and often travel to Vancouver for care at BC Children's Hospital and Sunny Hill Health Centre for Children.

Based on statistics, the twins were given a 20% chance of survival at birth . At birth at B.C. Women's Hospital & Health Centre, they were described as "wriggly, vigorous and very vocal." They weighed twelve and a half pounds, not six and a half pounds as reported by some media outlets, when they were born by caesarean section.

Maria and Teresa Tapia (born April 8, 2010) were conjoined twins born in the Dominican Republic. The twins were joined by their lower chest and abdomen and were therefore classified as omphalopagus sharing a liver, pancreas, and a small portion of their small intestine. On November 7, 2011, the twins underwent a successful separation surgery at the Children's Hospital of Richmond in Virginia.

Anastasia and Tatiana Dogaru

born August 29, 2004) are craniopagus conjoined twins. They were scheduled to begin the first of several surgeries to separate them at Rainbow Babies and Children's Medical Center in Cleveland, Ohio. However, in August 2007 the surgery was called off as too dangerous.

The twins were born in Rome, Italy to Romanian parents, Alin Dogaru, a Byzantine Catholic priest, and Claudia Dogaru, a nurse. Their mother heard about the successful separation of Egyptian-born twins who were also joined at the head and hoped her children could also be successfully separated. The Dogaru family — who also have an older daughter, Maria, and younger son Theodor — were brought to north Texas by the World Craniofacial Foundation to have Anastasia and Tatiana evaluated for possible separation.

The girls are currently developing normally for their age and speak both Romanian and English. They get around with Anastasia leading the way and Tatiana following. The top of Tatiana's head is attached to the back of Anastasia's. Anastasia, whose kidneys don't function, relies on her sister's kidneys, and Tatiana on her sister's circulatory system. The girls also share blood flow to the back of the brain and some brain matter. Doctors estimated the twins had only a 50 percent chance of surviving the surgery. There were also risks of complications, such as brain damage, but the girls also risk early death if they remain conjoined. Their parents believed separation would give them their best chance at living a normal life.

In May 2007, doctors used a catheter to insert wire coils into the veins of the two girls, successfully redirecting their blood flow. It was the first time the procedure was attempted in conjoined twins. Doctors pushed back the first of the planned separation surgeries to June 2007 while studying the complex circulatory system of the twins, but, in August of that year, decided it was too risky.

Foot binding was the custom of applying tight binding to the feet of young girls to modify the shape of their feet. The practice possibly originated among upper class court dancers during the Five Dynasties and Ten Kingdoms period in 10th century China, then became popular among the elite during the Song dynasty and eventually spread to all social classes by the Qing dynasty. Foot binding became popular as a means of displaying status (women from wealthy families, who did not need their feet to work, could afford to have them bound) and was correspondingly adopted as a symbol of beauty in Chinese culture. Foot binding limited the mobility of women, resulting in them walking in a swaying unsteady gait, although some women with bound feet working outdoor had also been reported. The prevalence and practice of foot binding varied in different parts of the country. Feet altered by binding were called lotus feet.

It has been estimated that by the 19th century, 40–50% of all Chinese women may have had bound feet, and up to almost 100% among upper class Han Chinese women. The Manchu Kangxi Emperor tried to ban foot binding in 1664 but failed. In the later part of the 19th century, Chinese reformers challenged the practice but it was not until the early 20th century that foot binding began to die out as a result of anti-foot-binding campaigns. Foot-binding resulted in lifelong disabilities for most of its subjects, and a few elderly Chinese women still survive today with disabilities related to their bound feet.

Queen bee syndrome was first defined by G.L. Staines, T.E. Jayaratne, and C. Tavris in 1973. It describes a woman in a position of authority who views or treats subordinates more critically if they are female. This phenomenon has been documented by several studies. In another study, scientists from the University of Toronto speculated that the queen bee syndrome may be the reason that women find it more stressful to work for women managers; no difference was found in stress levels for male workers. An alternate, though closely related, definition describes a queen bee as one who has succeeded in her career, but refuses to help other women do the same.

Following their separation surgery, both girls began learning to walk using crutches. Their parents have discussed having them eventually fitted with prosthetic legs. They also get around using wheelchairs or by crawling and pulling themselves up on furniture, according to the family's website. Jake and Erin Herrin's other children include fraternal twin sons and another daughter.

Middle school and high school seems to be the place in which the queen bee syndrome is born. Much research has been devoted to the investigation of the interactions of adolescent girls. This is where vicious bullying of teen girls shows up, often with the operations spearheaded by one individual, who has as of late been dubbed the "queen bee." In recent years, research has shown that adolescent girls form (often small) groups called cliques, which are often created based on a shared characteristic or quality of the members such as attractiveness or popularity. Association with such a group is often wanted by those who are part of the larger, all encompassing group, such as a class or school. It is the association with these groups that brings an individual similar treatment.

The Tanganyika laughter epidemic of 1962 was an outbreak of mass hysteriaor mass psychogenic illness (MPI)rumored to have occurred in or near the village of Kashasha on the western coast of Lake Victoria in the modern nation of Tanzania (formerly Tanganyika) near the border of Uganda.

The most common problem with bound feet was infection. Despite the amount of care taken in regularly trimming the toenails, they would often in-grow, becoming infected and causing injuries to the toes. Sometimes for this reason the girl's toenails would be peeled back and removed altogether. The tightness of the binding meant that the circulation in the feet was faulty, and the circulation to the toes was almost cut off, so any injuries to the toes were unlikely to heal and were likely to gradually worsen and lead to infected toes and rotting flesh. The necrosis of the flesh would also initially give off a foul odour, and later the smell may come from various microorganisms that colonized the folds.

If the infection in the feet and toes entered the bones, it could cause them to soften, which could result in toes dropping off; although, this was seen as a benefit because the feet could then be bound even more tightly. Girls whose toes were more fleshy would sometimes have shards of glass or pieces of broken tiles inserted within the binding next to her feet and between her toes to cause injury and introduce infection deliberately. Disease inevitably followed infection, meaning that death from septic shock could result from foot-binding, and a surviving girl was more at risk for medical problems as she grew older. It is thought that as many as 10% of girls may have died from gangrene and other infections due to footbinding.

At the beginning of the binding, many of the foot bones would remain broken, often for years. However, as the girl grew older, the bones would begin to heal. Even after the foot bones had healed, they were prone to re-breaking repeatedly, especially when the girl was in her teenage years and her feet were still soft. Bones in the girls' feet would often be deliberately broken again in order to improve the size or the shape of the feet. This was especially the case with the toes, as small toes were especially desirable. Older women were more likely to break hips and other bones in falls, since they could not balance securely on their feet, and were less able to rise to their feet from a sitting position. Other issues that might arise from foot binding included paralysis and muscular atrophy.

A fasting girl was one of a number of young Victorian girls, usually pre-adolescent, who claimed to be able to survive over indefinitely long periods of time without consuming any food or other nourishment. In addition to refusing food, fasting girls claimed to have special religious or magical powers.

The ability to survive without nourishment was attributed to some saints during the Middle Ages, including Catherine of Siena and Lidwina of Schiedam, and regarded as a miracle and a sign of sanctity. Numerous cases of fasting girls were reported in the late 19th century. Believers regarded such cases as miraculous.

In some cases, the fasting girls also exhibited the appearance of stigmata. Doctors, however, such as William A. Hammond ascribed the phenomenon to fraud and hysteria on the part of the girl. Historian Joan Jacobs Brumberg believes the phenomenon to be an early example of anorexia nervosa.

The hypothesis that those prone to extroversion or neuroticism, or those with low IQ scores, are more likely to be affected in an outbreak of hysterical epidemic has not been consistently supported by research. Bartholomew and Wesseley state that it “seems clear that there is no particular predisposition to mass sociogenic illness and it is a behavioural reaction that anyone can show in the right circumstances.”

Females are affected with mass psychogenic illness at greater rates than males. Adolescents and children are frequently affected in cases of MPI.

Dancing mania (also known as dancing plague, choreomania, St John's Dance and, historically, St. Vitus's Dance) was a social phenomenon that occurred primarily in mainland Europe between the 14th and 17th centuries. It involved groups of people dancing erratically, sometimes thousands at a time. The mania affected men, women, and children who danced until they collapsed from exhaustion. One of the first major outbreaks was in Aachen, in the Holy Roman Empire, in 1374, and it quickly spread throughout Europe; one particularly notable outbreak occurred in Strasbourg in 1518, also in the Holy Roman Empire.

Affecting thousands of people across several centuries, dancing mania was not an isolated event, and was well documented in contemporary reports. It was nevertheless poorly understood, and remedies were based on guesswork. Generally, musicians accompanied dancers, to help ward off the mania, but this tactic sometimes backfired by encouraging more to join in. There is no consensus among modern-day scholars as to the cause of dancing mania.

The several theories proposed range from religious cults being behind the processions to people dancing to relieve themselves of stress and put the poverty of the period out of their minds. It is, however, thought to have been a mass psychogenic illness in which the occurrence of similar physical symptoms, with no known physical cause, affect a large or small group of people as a form of social influence.

Mass psychogenic illness (MPI), also called mass sociogenic illness or just sociogenic illness, is "the rapid spread of illness signs and symptoms affecting members of a cohesive group, originating from a nervous system disturbance involving excitation, loss, or alteration of function, whereby physical complaints that are exhibited unconsciously have no corresponding organic" cause. MPI is distinct from other collective delusions, also included under the blanket terms of mass hysteria, in that MPI causes symptoms of disease, though there is no organic cause.

There is a clear preponderance of female victims. The DSM-IV-TR does not have specific diagnosis for this condition but the text describing conversion disorder states that "In 'epidemic hysteria', shared symptoms develop in a circumscribed group of people following 'exposure' to a common precipitant."

The laughter epidemic began on January 30, 1962, at a mission-run boarding school for girls in Kashasha. The laughter started with three girls and spread haphazardly throughout the school, affecting 95 of the 159 pupils, aged 12–18. Symptoms lasted from a few hours to 16 days in those affected. The teaching staff were not affected but reported that students were unable to concentrate on their lessons. The school was forced to close down on March 18, 1962.

After the school was closed and the students were sent home, the epidemic spread to Nshamba, a village that was home to several of the girls. In April and May, 217 people had laughing attacks in the village, most of them being school children and young adults. The Kashasha school was reopened on May 21, only to be closed again at the end of June. In June, the laughing epidemic spread to Ramashenye girls’ middle school, near Bukoba, affecting 48 girls.

The school from which the epidemic sprang was sued; the children and parents transmitted it to the surrounding area. Other schools, Kashasha itself, and another village, comprising thousands of people, were all affected to some degree. Six to eighteen months after it started, the phenomenon died off. The following symptoms were reported on an equally massive scale as the reports of the laughter itself: pain, fainting, flatulence, respiratory problems, rashes, attacks of crying, and random screaming. In total 14 schools were shut down and 1000 people were affected.

Tarantism is a form of hysteric behaviour, popularly believed to result from the bite of the wolf spider "Lycosa tarantula" (distinct from the broad class of spiders also called tarantulas).

A better candidate cause is "Latrodectus tredecimguttatus", commonly known as the Mediterranean black widow or steppe spider, although no link between such bites and the behaviour of tarantism has ever been demonstrated. However, the term historically is used to refer to a dancing mania - characteristic of southern Italy - which likely had little to do with spider bites. The tarantella dance supposedly evolved from this therapy.

The medical condition of being overweight or obesity is defined as "abnormal or excessive fat accumulation that may impair health". It is measured through the Body Mass Index (BMI), defined as a person's weight, in kilograms, divided by the square of the person's height, in meters. If an individual has a BMI of 25–29, he or she is overweight. Having a BMI of 30 or more means an individual is obese. The greater the BMI, the greater the risk of chronic diseases as a result of obesity. These diseases include cardiovascular diseases, diabetes, musculoskeletal disorders, cancer, and premature death.

The MONICA Project, sponsored by the World Health Organization, discovered that 30% of the population in the Arab World is overweight or obese, including adolescents and adults. This percentage is smaller for North African countries than oil-producing countries, but is still a prevalent trend. The spread of the Western lifestyle, defined as "the intake of attractive energy dense food with undesirable composition, increased consumption of animal fats and sugars and reduced consumption of dietary fiber, along with a lack of sufficient physical activity", is one of the leading causes. Specifically in the Arabian Peninsula, "physical activity of the population has significantly diminished with the availability of housemaids, private cars, television, and sophisticated household appliances. In addition, the types of food and fat intake have changed...".

Other common factors, besides a sedentary lifestyle and unhealthy food choices, across the Arab world include urbanization, technology, and a cultural appreciation of female plumpness and the practice of "leblouh" ("fattening").

The outbreaks of dancing mania varied, and several characteristics of it have been recorded. Generally occurring in times of hardship, up to tens of thousands of people would appear to dance for hours, days, weeks, and even months.

Women have often been portrayed in modern literature as the usual participants in dancing mania, although contemporary sources suggest otherwise. Whether the dancing was spontaneous, or an organised event, is also debated. What is certain, however, is that dancers seemed to be in a state of unconsciousness, and unable to control themselves.

In his research into social phenomena, author Robert Bartholomew notes that contemporary sources record that participants often did not reside where the dancing took place. Such people would travel from place to place, and others would join them along the way. With them they brought customs and behaviour that were strange to the local people. Bartholomew describes how dancers wore "strange, colorful attire" and "held wooden sticks".

Robert Marks, in his study of hypnotism, notes that some decorated their hair with garlands. However, not all outbreaks involved foreigners, and not all were particularly calm. Bartholomew notes that some "paraded around naked" and made "obscene gestures". Some even had sexual intercourse. Others acted like animals, and jumped, hopped and leaped about.

They hardly stopped, and some danced until they broke their ribs and subsequently died. Throughout, dancers screamed, laughed, or cried, and some sang. Bartholomew also notes that observers of dancing mania were sometimes treated violently if they refused to join in. Participants demonstrated odd reactions to the colour red; in "A History of Madness in Sixteenth-Century Germany", Midelfort notes they "could not perceive the color red at all", and Bartholomew reports "it was said that dancers could not stand... the color red, often becoming violent on seeing [it]".

Bartholomew also notes that dancers "could not stand pointed shoes", and that dancers enjoyed their feet being hit. Throughout, those affected by dancing mania suffered from a variety of ailments, including chest pains, convulsions, hallucinations, hyperventilation, epileptic fits, and visions. In the end, most simply dropped down, overwhelmed with exhaustion. Midelfort, however, describes how some ended up in a state of ecstasy. Typically, the mania was contagious but it often struck small groups, such as families and individuals.

The alternative view is that the dangers, such as from spiders, are overrated and not sufficient to influence evolution. Instead, inheriting phobias would have restrictive and debilitating effects upon survival, rather than being an aid. For some communities such as in Papua New Guinea, Cambodia and South America (except Chile, Colombia, Brazil, Uruguay, Argentina and Bolivia), spiders are included in traditional foods. This suggests arachnophobia may be a cultural, rather than genetic trait.