Sexología Forense
General Concepts and Forensic Applications of Sexology
Historically, sexuality was not considered an integral part of health and remained outside the scope of primary care. This changed in 1987 when the World Health Organization (WHO) defined sexual health as a basic human right. In forensic medicine, sexology is applied to determine sexual identity, reproductive capacity, and the capacity for copulation. Forensic Sexology is defined as the discipline that studies sex-related matters across medical, legal, and sociological aspects. Sex refers to the "morphological and functional characteristics that distinguish a male from a female," while sexuality is the dynamic function of sex, representing the erotic part of the sexual personality. According to Bonnet, medico-legal sexology is "the application of medical knowledge in any of its specialties to the solution of legal problems that sex may arise."
Diagnosis of Sex
The forensic expert frequently encounters the need to diagnose sex, such as in cases of newborns with ambiguous genitalia or transsexual individuals. A comprehensive diagnosis requires the evaluation of five key concepts: genetic sex, endocrine sex, morphological sex, psychological sex, and legal sex.
Genetic Sex
Genetic sex includes chromosomal and chromatin sex. Chromosomal sex is determined at fertilization by the union of the ovum and sperm. The normal human cell contains 46 chromosomes (44 autosomes and 2 sex chromosomes).
The absence of a Y chromosome leads to ovaries, while the presence of the "testis-determining factor" on the short arm of the Y chromosome leads to testicles. A karyotype is the ordered arrangement of chromosomes. Chromatin sex (Barr body) was discovered by Barr and Bertram in 1949. Female organisms typically have a chromatin corpuscle (drumstick shape) on the inner nuclear membrane. Chromatin is considered positive if present in $50\%$ or more of nuclei (female) and negative if in less than $5\%$ (male).
Endocrine Sex
This involves the hypothalamus-pituitary-gonadal axis. The hypothalamus secretes Gonadotropin-Releasing Hormone (GnRH), stimulating the anterior pituitary to produce Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH). In women, these produce estrogens and progesterone, regulating the uterus, vagina, and breasts. In men, FSH acts on Sertoli cells for spermatogenesis, and LH acts on Leydig cells to produce testosterone, which expands male sexual characteristics (voice, muscle development, hair distribution). Hormone levels for 17-beta estradiol, testosterone, and progesterone can be measured in blood and urine for forensic diagnosis.
Morphological Sex
This consists of primary and secondary sexual characteristics. Primary characteristics are internal and external organs for copulation. Secondary characteristics play dynamic roles in precopulatory behavior.
Primary Masculine: Epididymis, vas deferens, seminal vesicles, prostate, scrotum, penis. Primary Feminine: Fallopian tubes, uterus, vagina, vulva, clitoris, labia majora/minora. Secondary Masculine: Rudimentary breasts, shoulder girdle predominance, powerful locomotor system, typical fat distribution, rhomboid pubic hair, well-developed larynx (deep voice), receding hairline. Secondary Feminine: Developed breasts, pelvic girdle predominance, graceful locomotor system, typical female fat distribution, triangular pubic hair, high-pitched voice, no specific receding hairline.
Psychological and Legal Sex
Psychological sex is the intimate conviction of belonging to a specific sex regardless of genital morphology, often influenced by socio-environmental factors and "upbringing sex." Legal sex is the sex recorded in the Civil Registry at birth. Medical-legal experts must intervene when corrections are needed, particularly in cases of ambiguous genitalia.
Quantitative Disorders of Sexuality
Hyposexuality
Hyposexuality covers impotence (males) and frigidity (females). Impotence is the physical or psychic inability to perform a normal and complete sexual act. In men, it is often termed Erectile Dysfunction: "the persistent inability to achieve and maintain an erection sufficient for satisfactory sexual activity," typically requiring a 3-month duration for diagnosis.
Causes of Male Impotence:
Physiological: Age-related decline (starting at age 40). Hormones such as testosterone, growth hormone, and melatonin decrease.
Genital Pathology: Agenesis, phimosis, Peyronie's disease, or hypospadias.
Paragenital: Large hernias/hydroceles preventing penetration.
Clinical: Obesity, Diabetes (vascular/nerve damage to pudendal nerves), Hypothyroidism, Cushing's, or spinal cord injuries. Note: A thoracic spinal section allows tactile-induced erections but blocks psychic stimuli; a sacral lesion prevents all erections.
Toxic: Antidepressants, beta-blockers, alcohol, tobacco, and barbiturates.
Psychic: Selective impotence (impotent with wife but not others). Presence of nocturnal/morning erections proves the cause is psychic.
Female Hyposexuality: Includes frigidity, vaginismus (involuntary pelvic muscle contraction), and dyspareunia (painful coitus). Causes include fibrous hymen, vaginal septa, tumors, obesity, or psychological trauma.
Hipersexuality
This is an increase in desire (libido) or coital practice.
Satyriasis: Compulsive desire in men.
Nymphomania: Compulsive desire in women (divided into "Small" - platonic/solitary and "Great" - episodic loss of control).
Promiscuity: Increased sexual practice without pleasure. Causes can be psychological (manic phases, schizophrenia) or organic (psychomotor epilepsy, limbic system alterations).
Qualitative Disorders and Sexual Deviations (Parafilias)
The DSM refers to these as parafilias, characterized by unusual or grotesque fantasies/acts required for arousal. Forensic sexology deems a behavior acceptable if it involves consenting adults, causes no harm, and is practiced in private.
Homosexuality: Erotic attraction to the same sex. It is not listed as a disease in DSM-IV and is not a crime in Bolivia or Argentina unless harmful. Forensic distinction exists between "public" and "hidden" homosexuality. Types include Uranism (congenital) and Pederasty (acquired).
Transvestism: Sexual gratification by wearing clothes of the opposite sex.
Transsexualism: A desire to surgically and hormonally change one's body to the opposite sex. In Argentina, such surgeries are generally prohibited without judicial authorization (Law 17.132).
Fetishism: Sexual arousal through non-human objects or specific body parts ("partialism").
Sadism: Gratification from inflicting pain/humiliation. Named after the Marquis de Sade.
Masochism: Gratification from receiving pain. Sadomasochism (algolagnia) combines both.
Pedophilia/Paidophilia: Sexual attraction to minors. A major social problem exacerbated by the internet.
Necrophilia: Arousal from cadavers.
Saliromania: Arousal from damaging a body or clothes (e.g., throwing acid or ink).
Zoophilia/Bestialism: Sexual relations with animals (horses, dogs, sheep).
Exhibicionism: Exposing genitals to non-consenting observers in public.
Froteurism: Arousal from rubbing against others in crowded places.
Voyeurism: Arousal from secretly observing others undressing or having sex (mixoscopia/scopophilia).
Coprophilia/Urofilia/Clismafilia: Arousal from feces, urine, or enemas.
Gerontofilia: Attraction to the elderly.
Pigmalionism (Monumentofilia): Attraction to statues.
Dendrofilia: Sexual acts with plants.
Escatología Telefónica/Erotografomanía: Obscene calls or letters.
Riparofilia: Attraction to unwashed/dirty partners.
Medical-Legal Forensic Examination
Forensic evaluation of sexual function involves multiple domains:
Interrogation: History of trauma, libido changes, nocturnal erections (indicates psychic cause), family history, and medication (antidepressants, antihypertensives).
General/Genital Exam: Secondary sexual characteristics and genital integrity. Hymen evaluation (fibrous vs. imperforate) is crucial.
Endocrine/Neurological Exam: Hormonal dosages (Testosterone, FSH, LH) and glucose tests. Neurological tests include checking the bulbocavernosus and cremasteric reflexes.
Nocturnal Penile Tumescence (TPN): Uses sensors to monitor erections during REM sleep (occurring every 90 minutes). Absence of TPN indicates organic impotence; presence indicates psychogenic impotence.
Vascular Exam: Arteriography or Doppler ultrasound of pudendal/dorsal arteries. Intricavernous injection of papaverine or phentolamine.
Cytology (Urocitograma): Developed by the author, this method extracts cells from urine. Estrogens cause eosinophilic superficial cells in men (similar to ovulating women), proving the use of hormone treatments in transsexuals.
Deaths Related to Sexual Deviations
Asphyxia: Can occur during fellatio (aspiration or impaction). Autoerotic Asphyxia (Hypoxiphilia/Asphyxiophilia) involves intentional cerebral hypoxia via neck compression (ropes, belts) to increase masturbatory pleasure. Failure of the compression release mechanism leads to accidental hanging.
Electrical Shock: Use of stimulation devices in wet areas.
Genital Trauma: Induced by foreign objects for masturbation or "fisting" (hand in the rectum), leading to hemorrhage, peritonitis, or inhibitory sudden death.
Homicide/Suicide: Often related to jealousy in homosexual relationships or psychological conflict/extortion in hidden homosexuals.
Sudden Death: Vagal reflex during anal coitus.
Air Embolism: Possible in pregnant women during coitus forcing air into the utero-placental circulation.