The prevalence of pedophilia in the general population is not known, but is estimated to be lower than 5% among adult men. Less is known about the prevalence of pedophilia in women, but there are case reports of women with strong sexual fantasies and urges towards children. Most sexual offenders against children are male. Females may account for 0.4% to 4% of convicted sexual offenders, and one study estimates a 10 to 1 ratio of male-to-female child molesters. The true number of female child molesters may be underrepresented by available estimates, for reasons including a "societal tendency to dismiss the negative impact of sexual relationships between young boys and adult women, as well as women's greater access to very young children who cannot report their abuse", among other explanations.

The term "pedophile" is commonly used by the public to describe all child sexual abuse offenders. This usage is considered problematic by researchers, because many child molesters do not have a strong sexual interest in prepubescent children, and are consequently not pedophiles. There are motives for child sexual abuse that are unrelated to pedophilia, such as stress, marital problems, the unavailability of an adult partner, general anti-social tendencies, high sex drive, or alcohol use. As child sexual abuse is not automatically an indicator that its perpetrator is a pedophile, offenders can be separated into two types: pedophilic and non-pedophilic (or preferential and situational). Estimates for the rate of pedophilia in detected child molesters generally range between 25% and 50%. A 2006 study found that 35% of its sample of child molesters were pedophilic. Pedophilia appears to be less common in incest offenders, especially fathers and step-fathers. According to a U.S. study on 2429 adult male sex offenders who were categorized as "pedophiles", only 7% identified themselves as exclusive; indicating that many or most child sexual abusers may fall into the non-exclusive category.

Some pedophiles do not molest children. Little is known about this population because most studies of pedophilia use criminal or clinical samples, which may not be representative of pedophiles in general. Researcher Michael Seto suggests that pedophiles who commit child sexual abuse do so because of other anti-social traits in addition to their sexual attraction. He states that pedophiles who are "reflective, sensitive to the feelings of others, averse to risk, abstain from alcohol or drug use, and endorse attitudes and beliefs supportive of norms and the laws" may be unlikely to abuse children. A 2015 study indicates that pedophiles who molested children are neurologically distinct from non-offending pedophiles. The pedophilic molesters had neurological deficits suggestive of disruptions in inhibitory regions of the brain, while non-offending pedophiles had no such deficits.

According to Abel, Mittleman, and Becker (1985) and Ward "et al." (1995), there are generally large distinctions between the characteristics of pedophilic and non-pedophilic molesters. They state that non-pedophilic offenders tend to offend at times of stress; have a later onset of offending; and have fewer, often familial, victims, while pedophilic offenders often start offending at an early age; often have a larger number of victims who are frequently extrafamilial; are more inwardly driven to offend; and have values or beliefs that strongly support an offense lifestyle. One study found that pedophilic molesters had a median of 1.3 victims for those with girl victims and 4.4 for those with boy victims. Child molesters, pedophilic or not, employ a variety of methods to gain sexual access to children. Some groom their victims into compliance with attention and gifts, while others use threats, alcohol or drugs, or physical force.

Although what causes pedophilia is not yet known, researchers began reporting a series of findings linking pedophilia with brain structure and function, beginning in 2002. Testing individuals from a variety of referral sources inside and outside the criminal justice system as well as controls, these studies found associations between pedophilia and lower IQs, poorer scores on memory tests, greater rates of non-right-handedness, greater rates of school grade failure over and above the IQ differences, lesser physical height, greater probability of having suffered childhood head injuries resulting in unconsciousness, and several differences in MRI-detected brain structures. They report that their findings suggest that there are one or more neurological characteristics present at birth that cause or increase the likelihood of being pedophilic. Some studies have found that pedophiles are less cognitively impaired than non-pedophilic child molesters. A 2011 study reported that pedophilic child molesters had deficits in response inhibition, but no deficits in memory or cognitive flexibility. Evidence of familial transmittability "suggests, but does not prove that genetic factors are responsible" for the development of pedophilia. A 2015 study indicated that pedophilic offenders have a normal IQ.

Another study, using structural MRI, indicated that male pedophiles have a lower volume of white matter than a control group. Functional magnetic resonance imaging (fMRI) has indicated that child molesters diagnosed with pedophilia have reduced activation of the hypothalamus as compared with non-pedophilic persons when viewing sexually arousing pictures of adults. A 2008 functional neuroimaging study notes that central processing of sexual stimuli in heterosexual "paedophile forensic inpatients" may be altered by a disturbance in the prefrontal networks, which "may be associated with stimulus-controlled behaviours, such as sexual compulsive behaviours". The findings may also suggest "a dysfunction at the cognitive stage of sexual arousal processing".

Blanchard, Cantor, and Robichaud (2006) reviewed the research that attempted to identify hormonal aspects of pedophiles. They concluded that there is some evidence that pedophilic men have less testosterone than controls, but that the research is of poor quality and that it is difficult to draw any firm conclusion from it.

While not causes of pedophilia themselves, childhood abuse by adults or comorbid psychiatric illnesses—such as personality disorders and substance abuse—are risk factors for acting on pedophilic urges. Blanchard, Cantor, and Robichaud addressed comorbid psychiatric illnesses that, "The theoretical implications are not so clear. Do particular genes or noxious factors in the prenatal environment predispose a male to develop both affective disorders and pedophilia, or do the frustration, danger, and isolation engendered by unacceptable sexual desires—or their occasional furtive satisfaction—lead to anxiety and despair?" They indicated that, because they previously found mothers of pedophiles to be more likely to have undergone psychiatric treatment, the genetic possibility is more likely.

A study analyzing the sexual fantasies of 200 heterosexual men by using the Wilson Sex Fantasy Questionnaire exam determined that males with a pronounced degree of paraphilic interest (including pedophilia) had a greater number of older brothers, a high 2D:4D digit ratio (which would indicate low prenatal androgen exposure), and an elevated probability of being left-handed, suggesting that disturbed hemispheric brain lateralization may play a role in deviant attractions.

The following are some of the partialisms commonly found among people:

Until the 1990s, it tended to be described mostly as acrotomophilia, at the expense of other disabilities, or of the wish by some to pretend or acquire disability. Bruno (1997) systematised the attraction as factitious disability disorder. A decade on, others argue that erotic target location error is at play, classifying the attraction as an identity disorder. In the standard psychiatric reference "Diagnostic and Statistical Manual of Mental Disorders", text revision (DSM-IV-tr), the fetish falls under the general category of "Sexual and Gender Identity Disorders" and the more specific category of paraphilia, or sexual fetishes; this classification is preserved in DSM-5.

Attraction to disability or devotism is a sexualised interest in the appearance, sensation and experience of disability. It may extend from normal human sexuality into a type of sexual fetishism. Sexologically, the pathological end of the attraction tends to be classified as a paraphilia. (Note, however, that the very concept "paraphilia" continues to elude satisfactory definition and remains a subject of ongoing debate in both professional and lay communities) Other researchers have approached it as a form of identity disorder. The most common interests are towards amputations, prosthesis, and crutches.

In 2009 Amy Marsh, a clinical sexologist, surveyed the twenty-one English-speaking members of Erika Eiffel's 40-strong OS Internationale about their experiences. About half reported autism spectrum disorders: six had been diagnosed, four were affected but not diagnosed, and three of the remaining nine reported having "some traits." According to Marsh, "The emotions and experiences reported by OS people correspond to general definitions of sexual orientation," such as that in an APA article "on sexual orientation and homosexuality ... [which] refers to sexual orientation as involving 'feelings and self concept.'"

Object sexuality or objectophilia is a form of sexuality focused on particular inanimate objects. Those individuals with this expressed preference may feel strong feelings of attraction, love, and commitment to certain items or structures of their fixation. For some, sexual or even close emotional relationships with humans are incomprehensible. Some object-sexual individuals also often believe in animism, and sense reciprocation based on the belief that objects have souls, intelligence, and feelings, and are able to communicate.

Partialism is sexual interest with an exclusive focus on a specific part of the body other than the genitals. Partialism is categorized as a fetishistic disorder in the DSM-5 of the American Psychiatric Association only if it causes significant psychosocial distress for the person or has detrimental effects on important areas of their life. In the DSM-IV, it was considered a separate paraphilia (not otherwise specified), but was merged into fetishistic disorder by the DSM-5. Individuals who exhibit partialism sometimes describe the anatomy of interest to them as having equal or greater erotic attraction for them as do the genitals.

Partialism occurs in heterosexual, bisexual, and homosexual individuals. The foot is considered one of the most common partialisms.

Biphobia is aversion toward bisexuality and toward bisexual people as a social group or as individuals. It can take the form of denial that bisexuality is a genuine sexual orientation, or of negative stereotypes about people who are bisexual (such as the beliefs that they are promiscuous or dishonest). People of any sexual orientation can experience or perpetuate biphobia, and it is a source of social discrimination against bisexual people.

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.

Exhibitionism is the act of exposing in a public or semi-public context those parts of one's body that are not normally exposed – for example, the breasts, genitals or buttocks. The practice may arise from a desire or compulsion to expose themselves in such a manner to groups of friends or acquaintances, or to strangers for their amusement or sexual satisfaction or to shock the bystander. Exposing oneself only to an intimate partner is normally not regarded as exhibitionism. In law, the act of exhibitionism may be called indecent exposure, "exposing one's person", or other expressions.

Robot fetishism (also ASFR or technosexuality) is a fetishistic attraction to humanoid robots; also to people acting like robots or people dressed in robot costumes. A less common fantasy involves transformation into a robot. In these ways it is similar to agalmatophilia, which involves attraction to or transformation into statues or mannequins.

Robot fetishism can be viewed as a form of erotic anthropomorphism. When transformation or roleplaying is involved it can be thought of as a form of erotic objectification.

Vorarephilia (often shortened to vore) is a paraphilia characterized by the erotic desire to be consumed by, or sometimes to personally consume, another person or creature, or an erotic attraction to the process of eating in general. Since vorarephilic fantasies cannot usually be acted out in reality, they are often expressed in stories or drawings shared on the Internet. The word "vorarephilia" is derived from the Latin "vorare" (to "swallow" or "devour"), and Ancient Greek φιλία ("philía", "love").

The fantasy usually involves the victim being swallowed whole, though occasionally the victims are chewed up, and digestion may or may not be included. Vore fantasies are separated from sexual cannibalism because the living victim is normally swallowed whole. Sometimes the consumers are human, but anthropormorphized animals, dragons, and enormous snakes also appear frequently in these fantasies. After consumption, the enlarged belly of the consumer is often described with great care. Vorarephiles sometimes prefer to differentiate between "soft vore" and "hard vore"; soft vore means the victim is swallowed whole and alive, and may possibly come back out in the case of a "non-fatal" scenario, while in hard vore the victim goes through a more gruesome, realistic digestion process, often getting chewed up beforehand.

Vore is most often enjoyed through pictures, stories, videos, and video games, and it can appear in mainstream media. In some cases, vorarephilia may be described as a variation of macrophilia and may combine with other paraphilias. Apart from macrophilia, vore fantasies often have themes of BDSM, microphilia, pregnancy fetishism, furry fetishism, "unbirthing" (a desire to be swallowed whole into the vagina and returned to the uterus), and sexual cannibalism.

One case study analysis connected the fantasy with sexual masochism, and suggested that it could be motivated by a desire to merge with a powerful other or permanently escape loneliness. With "no known treatment" for vorarephiles who feel ill at ease with their sexuality, psychologists at Toronto's Centre for Addiction and Mental Health have recommended trying to "adjust to, rather than change or suppress" the sexual interest. Medication for sex drive reduction could be used if deemed necessary.

Diaper fetishists and diaper lovers (DLs) are often associated with adult babies, as both wear diapers, but the former do not engage in childlike behavior, while that is the distinguishing characteristic of adult babies (ABs). The majority of diaper lovers do not engage in any kind of infantile activity and are only interested in diapers. However, in certain individuals it is possible for an overlap to occur, as one can view themselves as neither exclusively an adult baby nor a diaper lover. Hence adult babies and diaper lovers collectively refer to themselves as AB/DLs. Diapers and rubber pants with "baby" prints are sold in adult sizes.

Some rubber and plastic fetishists have an affinity for diapers and rubber pants. In the case of disposable diapers, this attraction would be to their crinkly plastic backing. In the case of cloth diapers, it would be towards the latex or pvc of the pants worn over them.

Mechanophilia (or mechaphilia) is a paraphilia involving a sexual attraction to machines such as bicycles, motor vehicles, helicopters, ships, and aeroplanes.

Mechanophilia is treated as a crime in some nations with perpetrators being placed on a sex-offenders' register after prosecution. Motorcycles are often portrayed as sexualized fetish objects to those who desire them.

Spectrophilia is a fetish that is classified as the paraphilia in which one is attracted to ghosts or spirits. Spectrophiliacs fantasize about ghosts and often imagine scenarios involving sexual events between themselves or others and spirits.

Mysophilia relates to soiled or dirty material or people. Mysophiliacs may find dirt, soiled underwear, feces, or vomit to be sexually arousing.

It is possible for people with mysophilia to be aroused by unclean locales, such as an alleyway, or a dirty room/bathroom; wearing the same clothing for many days at a time; or not bathing, from mere days to several weeks.

Underwear fetishism is a sexual fetishism relating to undergarments, and refers to preoccupation with the sexual excitement of certain types of underwear, including panties, stockings, pantyhose, bras, or other items. Some people experience sexual excitement from wearing, while others get their excitement when observing or handling the underwear worn by another, or watching somebody putting underwear on/taking it off. Some may steal used underwear to get satisfaction. Not only does this include physical contact with the garment(s), or their wearers, but also includes arousal by printed or electronic image with depictions of underwear.

Underwear fetishism is not considered as paraphilia unless it causes distress or serious problems for the person or those associated with them.

The Internet has enabled people with this relatively rare paraphilia to discuss the subject and exchange anesthesia-related multimedia.

Medical fetishism refers to a number of sexual fetishes involving objects, practices, environments, and situations of a medical or clinical nature. In sexual roleplay a hospital or medical scene involves the sex partners assuming the roles of doctors, nurses, surgeons and patients to act out specific or general medical fetishes. Medical fantasy is a genre in pornography, though the fantasy may not necessarily involve pornography or sexual activity.

Medical fetishism may involve sexual attraction to respiratory therapy involving oxygen via nasal cannula or any sort of masks, medical practitioners, medical uniforms, hospital gowns, anaesthesia, intimate examinations (such as rectal examination, gynecological examination, urological examination, andrological examination, rectal temperature-taking), catheterization, diapering, enemas, injections, insertion (such as suppository insertion, menstrual-cup insertion, and prostatic massage), medical devices (such as orthopedic casts and orthopedic braces; see also "Abasiophilia"), dental objects (such as dental braces, retainers, and headgear), medical restraints, and medical gags.

Agalmatophilia (from the Greek "agalma" 'statue', and -philia φιλία = love) is a paraphilia involving sexual attraction to a statue, doll, mannequin or other similar figurative object. The attraction may include a desire for actual sexual contact with the object, a fantasy of having sexual (or non-sexual) encounters with an animate or inanimate instance of the preferred object, the act of watching encounters between such objects, or sexual pleasure gained from thoughts of being transformed or transforming another into the preferred object. Agalmatophilia may also encompass "Pygmalionism" (from the myth of Pygmalion), which denotes love for an object of one's own creation.

Jennifer Eve Rehor of San Francisco State University points out that such data as exists on what she calls "unconventional" or "kink" sexual behavior is generally problematic because of the way that it has been collected, through criminal and clinical case studies. Behavior that appears neither in criminal trials nor in clinical studies (for example, because the individuals concerned do not commonly seek professional help) is therefore under-reported. Rehor therefore surveyed 1,764 female participants in "kink" behavior (mostly association with BDSM) in 2010-11, receiving 1,580 valid responses. What Rehor calls "urine play" is relatively infrequent, with only 36.52% of her sample reporting having done it or having had it done to them. In contrast, 93.99% of her sample reported having done spanking or having had it done to them, and 61.96% reported having used or been exposed to feathers/fur. It is impossible to extrapolate Rehor's data onto the general population, but her study does give a guide to prevalence in the North American BDSM community.

Spectrophilia is sexual attraction to ghosts or sexual arousal from images in mirrors, as well as the phenomenon of sexual encounters between ghosts and humans.

Zoophilia is a paraphilia involving a sexual fixation on non-human animals. Bestiality is cross-species sexual activity between human and non-human animals. The terms are often used interchangeably, but some researchers make a distinction between the attraction (zoophilia) and the act (bestiality).

Although sex with animals is not outlawed in some countries, in most countries, bestiality is illegal under animal abuse laws or laws dealing with buggery or crimes against nature.