Introduction
You likely enjoy sex, drugs, and rock and roll, but society often views these urges as dangerous vices. You might wonder why these hedonistic pursuits feel so universal and irresistible to human nature.
Zoe Cormier argues that sex, drugs, and music are not moral failings, but fundamental biological drivers that have shaped human evolution and catalyzed scientific discovery. Pleasure is an ancient evolutionary tool that ensures survival, drives curiosity, and binds communities together.
The book explores the science behind these impulses through five key areas. You will discover how biology, chemistry, and neurology govern your most intense experiences.
- Why do your genes demand diverse sexual strategies?
- How do plant molecules hijack your brain chemistry?
- What makes music universally move the human mind?
1. Evolutionary Background of Sex
Sexual reproduction in the animal kingdom has driven the evolution of extreme and bizarre anatomical, chemical, and behavioral mechanisms. Animals exhibit vastly different strategies for fertilization, ranging from the spiralled penises and swirling vaginas of ducks that lead to forced copulation, to the keratinous barbs on cat penises designed to scrape out rival sperm and induce ovulation.
Sexual reproduction in the animal kingdom and human history reveals extreme anatomical adaptations and the unique role of pleasure.
Dutch scientists aboard the research vessel Dorada discovered how deep-sea squid Moroteuthis ingens reproduce by applying live male sperm capsules to a dead male's body, revealing that the capsules use protein-dissolving enzymes to melt through the female's flesh.
Animal reproduction shows wild diversity across species:
- 3 per cent of bird species boast external male genitals;
- 4 per cent of forced copulations result in ducklings in American biologist Dr Patricia Brennan's estimates.
Anatomical Discoveries
Human sex is biologically unrivalled in the animal kingdom due to the immense, prolonged pleasure it provides independent of procreation. While other primates engage in very brief bouts of sexual contact, humans have evolved the capacity for extended intercourse and profound pleasure, making the orgasm one of the most redeeming qualities of the human condition.
Bonobos only sustain a mating bout for fifteen seconds, and chimpanzees manage a mere seven seconds.
For centuries, anatomists and physicians incorrectly assumed the penis drove straight into the vagina like a sword into a sheath. Using magnetic resonance imaging, researchers disproved this long-held assumption. In 1999, Dutch researcher Pek Van Andel used an MRI scanner to image an acrobat couple performing intercourse, proving the penis bends responsively like a rubber boomerang.
Brain-mapping experiments show that sexual organs and related erotogenic zones have distinct, disproportionate representations in the somatosensory cortex. Neuroscientist Wilder Penfield and his contemporaries mapped the human brain by directly probing the grey matter of conscious epileptic patients undergoing brain surgery.
Orgasmic Diversity
Despite containing over 8,000 nerve endings and being designed solely for pleasure, the clitoris was infamously deemed useless by the father of anatomy, Andreas Vesalius, and later minimized by Sigmund Freud in favor of vaginal orgasms. Princess Marie Bonaparte underwent surgical repositioning of her clitoris twice by Viennese surgeon Josef Halban in her quest to achieve orgasm through penetration alone.
Pioneering sex surveys by Alfred Kinsey and Shere Hite demonstrated that sexual diversity is the norm and penetrative orgasm is a minority experience for women. Alfred Kinsey surveyed over 18,000 Americans and famously paid more than 300 men to masturbate on film to measure the velocity of ejaculate, while Shere Hite interviewed over 100,000 women for her landmark 1976 report.
Research into the G-spot and female ejaculation highlights a broad spectrum of normal physiological responses rather than a single standard of performance. Scientists like Beverly Whipple and John Perry documented the G-spot, female ejaculation containing prostatic acid phosphatase, and various orgasmic triggers, arguing against goal-oriented sex and societal pressure. Whipple and Perry studied a research subject who experienced 70 discrete orgasms in the laboratory in a single hour while her pubococcygeus muscle contractions were monitored.
Men frequently experience psychological anxiety regarding penis size, driven largely by misinformation and pornography, whereas women are generally satisfied. A 2002 study found that none of the 67 men seeking penile lengthening surgery actually fell below the clinical threshold of size that would merit medical alteration.
You can navigate these physiological realities when you remember several principles:
- Talk openly to enhance intimacy and pleasure;
- Avoid treating sex as a goal-oriented performance.
2. Hormones and Human Sexual Diversity
Hormones and neural chemistry shape human attraction, orientation, and reproduction in complex ways. You find that endocrinology governs your daily stress response and your sexual drives.
Hormones are powerful chemical messengers enabling distant organs to communicate, with cortisol playing a vital dual role as both essential for survival and poisonous when elevated chronically.
Charles-Édouard Brown-Séquard identified the adrenal glands as chemical factories producing cortisol, which shifts the body from rest-and-digest to fight-or-flight. Prolonged high levels of cortisol lead to stress-related agonies such as depression, chronic pain, and memory loss.
Between 1817 and 1874 marked the lifespan of Charles-Édouard Brown-Séquard. In 1856, he demonstrated that cortisol is essential for life by removing the adrenal glands from lab animals, resulting in their death.
The 1920s craze of transplanting animal testicles into aging men helped advance early endocrinology and laid the groundwork for modern xenotransplantation and the discovery of immune privilege in the testicles. Surgeons like Serge Voronoff and John Romulus Brinkley gained fame and fortune grafting animal testicle tissue into men. While largely based on the placebo effect and resulting in scar tissue, modern science has revealed that the testicles possess immune privilege due to Sertoli cells, which protect cells from the immune system and explain why xenotransplantation can sometimes succeed without immunosuppressants.
In 1920, Serge Voronoff grafted a 2-centimetre-sized slice of chimpanzee testicle into a man and later founded a farm in Italy to harvest apes. John Romulus Brinkley paid 500 dollars for his medical degree and charged 750 dollars per surgery, equivalent to over 10,000 dollars today, eventually earning an estimated 12 million dollars from goat testicle grafts.
Medical breakthroughs in sexual health often arise from serendipity and accidental discoveries rather than targeted research, as illustrated by the invention of Viagra. Sildenafil citrate, known by the chemical formula C22H30N6O4S and as Viagra, was originally tested in clinical trials as a treatment for jet lag and altitude sickness before researchers noticed the side effects. It works as a PDE5-inhibitor by blocking the enzyme phosphodiesterase type 5, preventing blood from escaping the spongy cavities of the penis.
Study subjects in clinical trials showed extreme reluctance to relinquish their potential jet lag cures at the trial's conclusion, helping researchers discover Viagra's true use.
The human brain's vast complexity allows it to find sexual gratification in a wide range of bizarre stimuli, illustrating that sexual variation is the norm. The spectrum of human paraphilias ranges from harmless fetishes like formicophilia and homeovestism to dangerous pathologies like somnophilia and paraphilic infantilism. Scientific studies demonstrate that plain vanilla sex is uniquely rare from an evolutionary standpoint.
Kenneth Pinyan died in 2005 due to a perforated colon incurred through receptive anal sex with a horse. Kinsey surveys found that 17 percent of American farm-working men had experienced sexual contact with animals to the point of orgasm, with an erect horse member reaching 40 inches.
Sexual Orientation Science
Homosexuality is shaped by a complex interaction of genetics, uterine environment, and hormones, and its historical classification as a pathology was undone through scientific studies and activism. Research into the fraternal birth order effect, brain structures like INAH3, and the major histocompatibility complex demonstrates biological underpinnings for homosexuality. Evelyn Hooker's standardized psychological tests and Dr. E. Fryer's disguised appearance at the 1972 APA meeting were instrumental in removing homosexuality from the DSM in 1973, a word that had entered the English lexicon in 1969.
Evelyn Hooker subjected 30 gay and 30 straight men to standardized tests like the Rorschach ink-blot test, proving there were no discernible psychiatric differences between the groups. Every older brother a man has increases his chance of being gay by 33 percent.
The development of reliable modern contraceptives, including barrier methods and the combined oral contraceptive pill, required a mix of botanical extraction, political determination, and accidental discoveries. Russell Marker extracted diosgenin from wild Mexican yams to synthesize progesterone cheaply, which later led to Gregory Pincus developing the combined progesterone-oestrogen pill through the Pincus Progesterone Project funded by Katherine Dexter McCormick and advocated by Margaret Sanger. Charles Goodyear invented vulcanised rubber in 1844, and Russell Marker founded Syntex in Mexico City in 1944 after being turned down by two different drug companies.
Human mate selection is heavily influenced by our oldest sense, smell, and the genetic markers of our immune system known as the major histocompatibility complex. The major histocompatibility complex codes for human leucocyte antigens that determine immune defense and shape individual body odor. Studies show that animals and humans tend to prefer the body odor of mates whose MHC genes differ from their own to prevent inbreeding and enhance offspring immunity, though contraceptive use can alter women's scent preferences.
In 2004, research on olfaction and nose receptors won a Nobel Prize. Humans possess 600 genes coding for odour receptors and 200 different genes coding for MHC proteins. Each human body hosts 100 trillion bacteria, studied through the Human Microbiome Project running from 2007 to 2012 at a total cost of 195 million dollars.
Monogamy in rare species like the prairie vole is governed by neurochemistry and epigenetic factors that control hormone receptor gene expression following mating. Prairie voles form lifelong pair-bonds due to high levels of oxytocin and vasopressin and the physical act of mating, which triggers epigenetic changes that increase hormone receptor sites in the brain. Epigenetic factors such as chemical methyl groups can turn genes on or off without altering the underlying DNA sequence.
Thomas Insel noted that mating causes a prairie vole to go from being intensely social to fiercely aggressive to all animals except its mate within hours.
Evolutionary psychology suggests that human anatomy and behaviour may also be adapted for promiscuity, including mechanisms of sperm displacement and female extra-pair copulations. Evolutionary psychologists argue that female unfaithfulness helps diversify offspring genetics to face unanticipated environmental problems. Anatomical features like the human coronal ridge are hypothesized to act as sperm displacement tools to scour out rival male semen from the vagina.
Gordon Gallup and his undergraduates used artificial phalluses and artificial vaginas filled with cornstarch-and-water semen to measure the volume displaced by artificial coitus.
3. Botanical Battles and Altered States
Psychoactive compounds evolved in plants as defense mechanisms but interact directly with human neural receptors to alter consciousness.
Plants developed astringent or poisonous chemicals to manipulate predator behavior or kill pests. These botanical compounds hijack the neural hardware of animals by interacting with their nervous system circuitry.
Nicotine is lethal to nearly all animals except primates, and bird deaths from tobacco butts are a frequent occurrence in modern cities. Nicotine was isolated in 1828 and its chemical structure was revealed in 1893.
Botanical Battles
The foundational discoveries of neural receptors and neurotransmitters were achieved by investigating how foreign botanical drugs affect the body. Scientists tracked down cellular receptors by observing how plant-derived molecules like nicotine and morphine mimic native human chemical messengers.
Sol Snyder located the opium receptor in 1973 by studying how morphine binds to tissue, which subsequently led to the discovery of natural endorphins in 1975. French scientists located the nicotinic acetylcholine receptor in the 1970s using snake toxins and electric eels. Delta-9-THC was identified in 1964, and the cannabinoid receptor was located in 1990.
Caffeine acts as a cognitive enhancer for pollinators, suggesting plants use it to ensure they revisit flowers and spread seeds. Exactly 100 plant species contain caffeine in their nectar. The structure of caffeine was revealed in 1881, and Emil Fischer received the Nobel Prize in 1902.
Experimental Revelations
Researchers have systematically administered psychoactive drugs to animals to study toxicity, behavioral changes, and the biological basis of addiction. Dr. Ronald Siegel spent 30 years studying the impacts of narcotics on animals.
Dr. Ronald Siegel conducted experiments with rhesus monkeys in dark isolation chambers where they voluntarily smoked DMT-laced cigarettes.
Sir Humphry Davy's systematic self-experimentation with nitrous oxide constituted the first methodical scientific investigation of a synthetic psychotropic drug. Joseph Priestley produced nitrous oxide in 1772, and Beddois and Watt proposed medical applications in a publication in 1794.
Davy built a portable box resembling a sedan chair to inhale 80 quarts of nitrous oxide and hosted late-night parties for literary figures like Coleridge and Southey to study the gas.
The Industrial Revolution and advances in chemistry allowed Victorian scientists to isolate, purify, and dramatically increase the potency of natural and synthetic drugs. Alfred Niemann isolated cocaine's active alkaloid in 1860, while caffeine, nicotine, and theobromine were isolated earlier in the century.
Bayer created Heroin as a supposedly non-addictive alternative to morphine, only to discover it acts as an efficient ballistic delivery system for morphine into the central nervous system.
LSD was synthesized during research into the medical uses of ergot alkaloids, leading to the accidental discovery of its profound psychedelic properties. Albert Hofmann, working for Sandoz laboratories, investigated the parasitic fungus Claviceps purpurea to find compounds useful for obstetrics and migraine treatment before accidentally absorbing LSD-25 and experiencing the world's first recorded acid trip.
Roughly 20,000 people died from ergotism in Aquitaine in 944, and the last known major ergot poisoning outbreak occurred in southern Russia in 1926. Hofmann produced LSD-25 in 1938.
Hofmann accidentally absorbed a tiny amount of LSD solution through his fingertips on April 16, 1943, and subsequently undertook a planned self-experiment with 0.25 milligrams of lysergic acid diethylamide tartrate, followed by his famous bicycle ride home.
4. Renegade Research and Addiction
Mind-altering substances have catalyzed scientific breakthroughs, therapeutic advances, and insights into addiction.
Dock Ellis struggled with stimulants and accidentally took large doses of LSD on the day of a game. He hopped on a plane to San Diego while tripping on LSD, struggled to recognize the ball's size, and pitched a rare no-hitter because the chemical helped him cope with his fear of failure.
When government funding for nuclear research dried up after the Cold War, unemployed or underemployed physicists formed the Fundamental Fysiks Group in California. They combined quantum physics with new-age ideals and psychedelics to revive interest in forgotten theoretical frameworks. Physicists in California formed the Fundamental Fysiks Group, hosting hot-bulb hallucinogen parties while bringing neglected quantum mechanics concepts back into serious academic research.
Kary Mullis conceived the mechanism for PCR while driving on a mountain road under the influence of LSD. He visualized coiled DNA chains that helped him solve the challenge of how to read genomes. Kary Mullis used LSD, which helped him visualize the spiraling string of DNA and devise chemical primers to shatter and replicate fragments of genetic code, earning him the Nobel Prize in 1993.
Renegade Research
Alexander Shulgin used proceeds from a biodegradable insecticide he developed at Dow Chemical to set up a home laboratory. He synthesized and tested thousands of novel chemicals on himself, his wife, and friends, eventually publishing his findings in comprehensive chemical compendiums. Alexander Shulgin discovered the psychoactive properties of MDMA after ingesting it in 1976 and later published PiHKAL and TiHKAL to preserve the formulas before regulatory bodies could suppress them.
Bruce Alexander challenged early animal studies where isolated caged rats self-administered drugs until death. He created Rat Park, an enriched environment with ample space, toys, and social interaction, showing that rats in comfortable conditions consumed significantly fewer opiates. Bruce Alexander placed morphine-addicted rats into Rat Park instead of barren cages, observing that they voluntarily chose plain water over morphine-laced water when given social and physical stimulation.
Studies by researchers like Nicole Avena show that sugar and fat-rich foods stimulate dopamine receptor activation akin to doses of morphine or cocaine. Rats dosed with sugar show overlapping neural circuits and dopamine patterns in brain scans that mirror animals exposed to addictive chemical substances.
Surgery of the Soul
Teri Krebs and Pål-Ørjan Johansen pooled data from older clinical trials and found that a significant majority of participants who received a single dose of LSD reported lower levels of alcohol consumption compared to a placebo group. Teri Krebs and Pål-Ørjan Johansen analyzed six trials involving 536 people and discovered that 59 per cent of those given LSD reported reduced alcohol consumption.
Ketamine targets the glutamate system and triggers synaptogenesis, which is the formation of new neural connections. This process reduces depressive symptoms within 72 hours, though it carries severe risks of bladder and organ damage. Double-blind tests administered ketamine to 17 acutely depressed patients who failed conventional treatments, finding that their depressive symptoms improved after just 72 hours.
Brain-imaging studies by researchers like Robin Carhart-Harris and Draulio de Araujo show that psilocybin and ayahuasca decrease blood flow through maximal hub regions known as the default mode network. Robin Carhart-Harris used fMRI scanners on people dosed with psilocybin and discovered that brain activity decreased in regions like the thalamus and medial prefrontal cortex rather than increasing.
5. The Origin and Neuroscience of Sound
Music is an ancient human constant that stimulates the entire brain and relies on specialized evolutionary auditory structures.
Origins of Music
Archaeologist Ivan Turk found a bear bone fragment in a Slovenian cave in 1995. This Divje Babe flute features evenly spaced holes comparable to modern wind instruments and dates back 40,000 years. Ivan Turk and musician Ljuben Dimkaroski built a replica of the instrument in 2011 based on musicologist Bob Fink's model, revealing a functional instrument with a two-octave range.
Modern humans share genetic material with Neanderthals and evolved anatomical changes in the vocal tract that enabled singing and complex speech. Researchers analyzing ancient cave paintings in Arcy-sur-Cure, France, found the highest density of art located at points with the best acoustics for resonance and echoes.
Neuroscience of Sound
The human sacculus, an ancient evolutionary structure inherited from fish, responds directly to loud low-frequency bass notes. Originally part of the lateral line network and otoliths in fish for sensing water motion, the sacculus in humans functions mainly for balance. However, studies show it responds to loud tones between 300 and 350 hertz at volumes above 90 decibels, linking hearing directly to the hypothalamus and autonomic responses.
Professor William Jamie Tyler noticed unexpected spikes in the activity of dissected neurons on his lab bench every time his subwoofer boomed while listening to music late at night.
The tiny bones of the mammalian middle ear evolved from the jaw bones of ancient reptiles through exaptation. The malleus, incus, and stapes are the smallest bones in the human body. In reptiles and amphibians, the equivalent structures form part of the jaw joint.
Palaeoanthropologist Rolf Quam examined ossicles from a 1.8-million-year-old Paranthropus robustus specimen and compared them to Australopithecus africanus to study human evolutionary traits. Because of their delicate biomechanical structure, these ossicles grow very little throughout a person's life, earning them the term relic bones.
10 Key Ideas
- Human sex is biologically unrivalled in the animal kingdom due to the immense, prolonged pleasure it provides independent of procreation, making the orgasm one of the most redeeming qualities of the human condition.
- Homosexuality is shaped by a complex interaction of genetics, uterine environment, and hormones, and its historical classification as a pathology was undone through scientific studies and activism.
- Evolutionary psychology suggests that human anatomy and behaviour may also be adapted for promiscuity, including mechanisms of sperm displacement and female extra-pair copulations.
- Psychoactive compounds evolved in plants as defense mechanisms but interact directly with human neural receptors to alter consciousness.
- The foundational discoveries of neural receptors and neurotransmitters were achieved by investigating how foreign botanical drugs affect the body.
- The Industrial Revolution and advances in chemistry allowed Victorian scientists to isolate, purify, and dramatically increase the potency of natural and synthetic drugs.
- Mind-altering substances have catalyzed scientific breakthroughs, therapeutic advances, and insights into addiction.
- Bruce Alexander placed morphine-addicted rats into Rat Park instead of barren cages, observing that they voluntarily chose plain water over morphine-laced water when given social and physical stimulation.
- Ketamine targets the glutamate system and triggers synaptogenesis, which is the formation of new neural connections, reducing depressive symptoms within 72 hours.
- Music is an ancient human constant that stimulates the entire brain and relies on specialized evolutionary auditory structures.