The prevalence of fetishism is not known with certainty. The majority of fetishists are male. In a 2011 study, 30% of men reported fetishistic fantasies, and 24.5% had engaged in fetishistic acts. Of those reporting fantasies, 45% said the fetish was intensely sexually arousing. In a 2014 study, 26.3% of women and 27.8% of men acknowledged any fantasies about "having sex with a fetish or non-sexual object". A content analysis of the sample's favorite fantasies found that 14% of the male fantasies involved fetishism (including feet, nonsexual objects, and specific clothing), and 4.7% focused on a specific body part other than feet. None of the women's favorite fantasies had fetishistic themes. Another study found that 28% of men and 11% of women reported fetishistic arousal (including feet, fabrics, and objects "like shoes, gloves, or plush toys"). 18% of men in a 1980 study reported fetishistic fantasies.

Fetishism to the extent that it becomes a disorder appears to be rare, with less than 1% of general psychiatric patients presenting fetishism as their primary problem. It is also uncommon in forensic populations.

Fetishism usually becomes evident during puberty, and may develop prior to that. No cause for fetishism has been conclusively established.

Some explanations invoke classical conditioning. In several experiments, men have been conditioned to show arousal to stimuli like boots, geometric shapes or penny jars by pairing these cues with conventional erotica. According to John Bancroft, conditioning alone cannot explain fetishism, because it does not result in fetishism for most people. He suggests that conditioning combines with some other factor, such as an abnormality in the sexual learning process.

Theories of sexual imprinting propose that humans learn to recognize sexually desirable features and activities during childhood. Fetishism could result when a child is imprinted with an overly narrow or "incorrect" concept of a sex object. Imprinting seems to occur during the child's earliest experiences with arousal and desire, and is based on "an egocentric evaluation of salient reward- or pleasure-related characteristics that differ from one individual to another."

Neurological differences may play a role in some cases. Vilayanur S. Ramachandran observed that the region processing sensory input from the feet lies immediately next to the region processing genital stimulation, and suggested an accidental link between these regions could explain the prevalence of foot fetishism. In one unusual case, an anterior temporal lobectomy relieved an epileptic man's fetish for safety pins.

Various explanations have been put forth for the rarity of female fetishists. Most fetishes are visual in nature, and males are thought to be more sexually sensitive to visual stimuli. Roy Baumeister suggests that male sexuality is unchangeable, except for a brief period in childhood during which fetishism could become established, while female sexuality is fluid throughout life.

Transvestism is the practice of dressing and acting in a style or manner traditionally associated with the opposite sex. In some cultures, transvestism is practiced for religious, traditional or ceremonial reasons.

Males with late onset gender dysphoria "frequently" display transvestic fetishism.

Some male transvestic fetishists collect women's clothing, e.g. panties, nightgowns, babydolls, bridal gowns, slips, brassieres, and other types of nightwear, lingerie, stockings, pantyhose, shoes, and boots, items of a distinct feminine look and feel. They may dress in these feminine garments and take photographs of themselves while living out their fantasies.

According to DSM-IV, this fetishism was limited to heterosexual men; however, DSM-5 does not have this restriction, and opens it to women and men with this interest, regardless of their sexual orientation.

There are two key criteria before a psychiatric diagnosis of "transvestic fetishism" is made:

1. Individuals must be sexually aroused by the act of cross-dressing.

2. Individuals must experience significant distress or impairment – socially or occupationally – because of their behavior.

Gender identity is a concept, specifically psychological, that refers to one's sense of being a male or female in regards to sexual orientation. Individuals who are diagnosed with gender identity disorder are classified as being dissatisfied with their anatomically determined gender.

Transvestic fetishism is a psychiatric diagnosis applied to those who are thought to have an excessive sexual or erotic interest in cross-dressing; this interest is often expressed in autoerotic behavior. It differs from cross-dressing for entertainment or other purposes that do not involve sexual arousal, and is categorized as a paraphilia in the Diagnostic and Statistical Manual of the American Psychiatric Association. (Sexual arousal in response to donning sex-typical clothing is homeovestism.)

Psychosexual disorders can vary greatly in severity and treatability. Medical professionals and licensed therapists are necessary in diagnosis and treatment plans. Treatment can vary from therapy to prescription medication. Sex therapy, behavioral therapy, and group therapy may be helpful to those suffering distress from sexual dysfunction. More serious sexual perversions may be treated with androgen blockers or selective serotonin reuptake inhibitors (SSRIs) to help restore hormonal and neurochemical balances.

Symptoms of GD in children may include any of the following: disgust at their own genitalia, social isolation from their peers, anxiety, loneliness and depression. According to the American Psychological Association, transgender children are more likely to experience harassment and violence in school, foster care, residential treatment centers, homeless centers and juvenile justice programs than other children.

Adults with GD are at increased risk for stress, isolation, anxiety, depression, poor self-esteem and suicide. Studies indicate that transgender people have an extremely high rate of suicide attempts; one study of 6,450 transgender people in the United States found 41% had attempted suicide, compared to a national average of 1.6%. It was also found that suicide attempts were less common among transgender people who said their family ties had remained strong after they came out, but even transgender people at comparatively low risk were still much more likely to have attempted suicide than the general population. Transgender people are also at heightened risk for certain mental disorders such as eating disorders.

GID exists when a person suffers discontent due to gender identity, causing them emotional distress. Researchers disagree about the nature of distress and impairment in people with GID. Some authors have suggested that people with GID suffer because they are stigmatized and victimized; and that, if society had less strict gender divisions, transsexual people would suffer less.

A twin study (based on seven people in a 314 sample) suggested that GID may be 62% heritable, indicating the possibility of a genetic influence or prenatal development as its origin, in these cases.

To determine relative prevalences of different fetishes, Italian researchers obtained an international sample of 5,000 individuals from 381 fetish-themed discussion groups. The relative prevalences were estimated based on (a) the number of groups devoted to a particular fetish, (b) the number of individuals participating in the groups and (c) the number of messages exchanged. Within the sample population (a population of adults online involved in sexual discussion), 12 percent indicated a fetish related to an "object associated with the body + external event" . This includes, but is not limited to, objects such as underwear, socks, shoes, etc. (see Table 1 in the .pdf of the first article cited).

Some people experience sexual excitement from the look or feel of a women's bra. The attraction may be to the look or feel of the material, such as lace, or how it looks on a person. Some people get excitement from removing a bra.

Uniform fetishism is a sexual fetishism where an individual is sexually aroused by uniforms.

Gender dysphoria in children or gender identity disorder in children (GIDC) is a formal diagnosis used by psychologists and physicians to describe children who experience significant discontent (gender dysphoria) with their biological sex, assigned gender, or both.

GIDC was formalized in the third revision of the "Diagnostic and Statistical Manual of Mental Disorders" (DSM-III) in 1980 and primarily referenced gender non-conforming behaviors. GIDC remained in the DSM from 1980 to 2013, when it was replaced with the diagnosis of "gender dysphoria" in the fifth revision (DSM-5), in an effort to diminish the stigma attached to gender variance while maintaining a diagnostic route to gender affirming medical interventions such as hormone therapy and surgery.

Controversy surrounding the pathologization and treatment of cross-gender identity and behaviors, particularly in children, has been evident in the literature since the 1980s. Proponents of more widespread GIDC diagnoses argue that therapeutic intervention helps children be more comfortable in their bodies and can prevent adult gender identity disorder. Opponents say that the equivalent therapeutic interventions with gays and lesbians (titled conversion or reparative therapy) have been strongly questioned or declared unethical by the American Psychological Association, American Psychiatric Association, American Association of Social Workers and American Academy of Pediatrics. The World Professional Association for Transgender Health (WPATH) states that treatment aimed at trying to change a person's gender identity and expression to become more congruent with sex assigned at birth "is no longer considered ethical." Critics also argue that the GIDC diagnosis and associated therapeutic interventions rely on the assumption that an adult transsexual identity is undesirable, challenging this assumption along with the lack of clinical data to support outcomes and efficacy.

Gender identity disorder in children is more heavily linked with adult homosexuality than adult transsexualism. According to limited studies, the majority of children diagnosed with GID cease to desire to be the other sex by puberty, with most growing up to identify as gay or lesbian with or without therapeutic intervention.

Children with persistent GID are characterized by more extreme gender dysphoria in childhood than children with desisting gender dysphoria. Some (but not all) gender diverse / gender independent / gender fluid youth will want or need to transition, which may involve social transition (changing dress, name, pronoun), and, for older youth and adolescents, medical transition (hormonal and surgical intervention). Treatment may take the form of puberty blockers such as Lupron Depot or Leuprolide Acetate, or cross-sex hormones (i.e., administering estrogen to an assigned male at birth or testosterone to an assigned female at birth), or surgery (i.e., mastectomies, salphingo-oophorectomies/hysterectomy, the creation of a neophallus in female-to-male transsexuals, orchiectomies, breast augmentation, facial feminization surgery, the creation of a neovagina in male-to-female transsexuals), with the aim of bringing one’s physical body in line with their felt gender. The ability to transition (socially and medically) are sometimes needed in the treatment of gender dysphoria.

The Endocrine Society does not recommend endocrine treatment of prepubertal children because clinical experience suggests that GID can be reliably assessed only after the first signs of puberty. It recommends treating transsexual adolescents by suppressing puberty with puberty blockers until age 16 years old, after which cross-sex hormones may be given.

The University of Washington is leading the largest study of transgender youth ever conducted. The study, known as the Transgender Youth Project, looks at 300 transgender kids between the ages of 3 and 12. Researchers hope to follow the children for 20 years.

Transmisogyny (sometimes trans-misogyny) is the intersection of transphobia and misogyny. Transphobia is defined as "the irrational fear of, aversion to, or discrimination against transgender or transsexual people". Misogyny is defined as "a hatred of women". Therefore, transmisogyny includes negative attitudes, hate, and discrimination of transgender or transsexual individuals who fall on the feminine side of the gender spectrum, particularly transgender women. The term was coined by Julia Serano in her 2007 book "Whipping Girl" and used to describe the unique discrimination faced by trans women because of "the assumption that femaleness and femininity are inferior to, and exist primarily for the benefit of, maleness and masculinity", and the way that transphobia intensifies the misogyny faced by trans women (and vice versa). It is said many trans women experience an additional layer of misogyny in the form of fetishization; Serano talks about how society views trans women in certain ways that sexualize them, such as them transitioning for sexual reasons, or ways where they’re seen as sexually promiscuous.Transmisogyny is a central concept in transfeminism and is commonly referenced in intersectional feminist theory. That trans women's femaleness (rather than only their femininity) is a source of transmisogyny is denied by certain radical feminists, who claim that trans women are not female.

Though coined as late as the 1910s, the phenomenon is not new. It was referred to in the Hebrew Bible. The word has undergone several changes of meaning since it was first coined and is still used in a variety of senses. Today, the term "transvestite" is commonly considered outdated and derogatory, with the term "cross-dresser" used as a more appropriate replacement. This is because the term "transvestite" was historically used to diagnose medical disorders, including mental health disorders, and transvestism was viewed as a disorder, but the term "cross-dresser" was coined by the transgender community. In some cases, however, the term "transvestite" is seen as more appropriate for use by members of the transgender community instead of by those outside of the transgender community, and some have reclaimed the word.

Among the most common uniforms in uniform fetish are those of a police officer, prison officer, soldier, schoolgirl, nurse, French maid, waitress, cheerleader, and Playboy Bunny. Some people also regard nuns' habits or even aprons as uniforms. The uniforms may be genuine, realistic, or they may be sexualized through the use of a very short miniskirt, a very long hobble skirt or a corset, through the use of stockings, fishnet tights, or high heels, or by being made of leather or latex, according to preference. Sometimes uniforms are used according to what activity is being done. For example, someone may wear a nurse's uniform to administer an enema or a police uniform to handcuff and cage someone. Two people may dress as inmates for cell mate-on-cell mate activities in a prison setting or as a submissive to a third (prison guard) roleplayer. This may add a sense of authenticity to the game play. A stripper dressed as a police officer is a popular fixture at birthday and bachelor parties. The "officer" begins with a mock "arrest", often using handcuffs, of the guest of honor before going into a dance routine.

Transmisogyny is generally understood to be caused by the social belief that men are superior to women. In "Whipping Girl", Julia Serano writes that the existence of trans women is seen as a threat to a "male-centered gender hierarchy, where it is assumed that men are better than women and that masculinity is superior to femininity". Gender theorist Judith Butler echoes this assumption, stating that the murder of transgender women is "an act of power, a way of re-asserting domination... killing establishes the killer as sovereign in the moment that he kills".

Trans women are also viewed as threatening the heterosexuality of cisgender men. In media, "deceivers" such as Dil, a transgender woman from the 1992 film "The Crying Game", have been observed to invoke outrage and male homophobia in an audience when their "true" maleness is unveiled.

A disability pretender is subculture term meaning a person who behaves as if he or she were disabled. It may be classified as a type of factitious disorder or as a medical fetishism.

One theory is that pretenders may be the "missing link" between devotees and wannabes, demonstrating an assumed continuum between those merely attracted to people with disabilities and those who actively wish to become disabled. Many wannabes use pretending as a way to appease the intense emotional pain related to having body integrity identity disorder.

Pretending takes a variety of forms. Some chatroom users on internet sites catering to devotees have complained that chat counterparts they assumed were female were revealed as male devotees. This form of pretending (where a devotee derives pleasure by pretending to be a disabled woman) may indicate a very broad predisposition to pretending among devotees.

Pretending includes dressing and acting in ways typical of disabled people, including making use of aids (Walking sticks, crutches, wheelchairs, mobility scooters, white canes, etc. Pretending may also take the form of a devotee persuading his or her sexual partner to play the role of a disabled person. Pretending may be practiced in private, in intimacy, or in public, and may occupy surprisingly long periods. In the latter case, some pretenders hope that the disability may become permanent, such as through tissue necrosis caused by constricted blood supply.

A specific fear of clowns has sometimes been discussed in terms of a specific phobia. The term "" is a neologism coined in the context of informal ""-phobia" lists".

The term is not listed in the World Health Organisation's ICD-10 nor in the American Psychiatric Association's DSM-5 categorization of disorders.

Psychogenic alopecia, also called "over-grooming" or "psychological baldness," is a compulsive behavior that affects domestic cats. Generally, psychogenic alopecia does not lead to serious health consequences or a decreased lifespan.

Grooming is a natural behavior for cats. Cats spend 5%-25% of their waking hours grooming. Grooming becomes excessive when it takes precedence over other activities or no longer seems functional. Excessive grooming, which can lead to hair loss, skin wounds, and ulceration, can result from chronic stress or develop in cats who already exhibit nervous temperaments. Even when the source of stress is resolved or removed, excessive grooming may continue. There may be some genetic basis for the behavior, and it predominantly affects purebred cats of oriental breeds, but can develop in any feline. Female cats appear more susceptible. Environmental factors suspected of causing over grooming include flea allergy, boredom, food allergy, dust or pollen causing an allergic reaction, constipation and/or urinary tract infection caused by avoidance of a dirty litter tray, dermatitis, anxiety caused by inconsistent meal times. Deprivation of sunlight could be the part of the problem for indoors only cats.

Foreign language anxiety, or xenoglossophobia, is the feeling of , worry, nervousness and apprehension experienced in learning or using a second or foreign language. The feelings may stem from any second language context whether it is associated with the productive skills of speaking and writing or the receptive skills of reading and listening.

Foreign language anxiety is a form of what psychologists describe as a "specific anxiety reaction". Some individuals are more predisposed to anxiety than others and may feel anxious in a wide variety of situations. Foreign language anxiety, however, is situation-specific and so it can also affect individuals who are not characteristically anxious in other situations.

Examples of psychomotor retardation include the following:

- Unaccountable difficulty in carrying out what are usually considered "automatic" or "mundane" self-care tasks for healthy people (i.e., without depressive illness) such as taking a shower, dressing, self-grooming, cooking, brushing one's teeth and exercising.

- Physical difficulty performing activities which normally would require little thought or effort such as walking up a flight of stairs, getting out of bed, preparing meals and clearing dishes from the table, household chores or returning phone calls.

- Tasks requiring mobility suddenly (or gradually) and inexplicably seem to be "impossible". Activities such as shopping, getting groceries, caring for the daily needs of one's children and meeting the demands of employment or school are commonly affected. Individuals experiencing these symptoms typically sense that something is wrong, and may be confused about their inability to perform these tasks.

- Activities usually requiring little mental effort can become challenging. Balancing one's checkbook, making a shopping list or making decisions about mundane tasks (such as deciding what errands need to be done) are often difficult.

In schizophrenia, activity level may vary from psychomotor retardation to agitation; the patient will experience periods of listlessness and may be unresponsive, and at the next moment be active and energetic.

In the "Space To Care" study aimed at improving hospital design for children, researchers from the University of Sheffield polled 250 children regarding their opinions on décor for a forthcoming hospital redesign; all 250 children, whose ages ranged between four and sixteen, reported that they disliked clowns as part of hospital décor. Many of them, including some older children, stated in the poll that they, in fact, actively feared clowns. In other studies playing with therapeutic clowns reduced anxiety in children and improved healing in children with respiratory illness.