The Speech of Monkeys

In Short

This landmark treatise argues that monkeys possess a genuine, structured spoken language rather than mere instinctive cries. Through meticulous observation in city parks, personal apartments, and early laboratory settings, the author documents specific vocal signals for submission, alarm, and desire. By capturing these sounds on Edison's newly invented phonograph, the text attempts to prove that human speech and animal utterances differ only in degree, not in kind. The book remains a fascinating historical artifact, bridging nineteenth-century natural history and the birth of modern bioacoustics through its blend of earnest observational science, philosophical speculation, and eccentric animal portraits.

The Story

The argument begins with a challenge to the traditional divide between human reason and animal instinct. The narrative establishes that expression develops along an evolutionary spectrum: lower forms of life rely primarily on physical gestures supplemented by basic sounds, while higher forms prioritize vocal sounds accented by gestures. To demonstrate that Simian vocalizations constitute genuine speech, the investigation applies the same empirical methods used by an explorer interpreting an unknown human tongue. By pairing specific, repeatable sounds with observable actions, the study seeks to isolate the foundational phonetic elements of animal communication.

To move beyond subjective human listening, the research relies heavily on the phonograph. Recording monkey voices onto wax cylinders allows for precise acoustic testing. By playing these recorded calls back to captive subjects, the work observes immediate, predictable responses, confirming that the sounds carry distinct meanings across individuals of the same species. Reversing the phonograph cylinders reveals that pure musical tones remain unchanged in reverse, whereas Simian speech sounds alter slightly—proving they are compound sounds built upon complex phonetic structures. The investigation notes that while monkey speech lacks most English vowel sounds like a, i, or o, it relies heavily on a flexible u sound (resembling the "oo" in "shoot"), accompanied by rudimentary consonants that help launch each utterance.

From these technical experiments, the narrative expands into broader observations of cognitive capacity. Testing monkeys with mirrors, hanging bells, and hidden items of varying sizes reveals their rudimentary grasp of concrete numbers, color selection, and cause-and-effect mechanics. The work maintains that when placed in unfamiliar settings, a monkey acts through genuine reasoning rather than blind habit. The argument traces this communicative drive down through the animal kingdom, proposing that the impulse to express thought spans all living matter, from mammals to the humblest organic forms.

In its final movement, the work turns into a scathing critique of human self-conceit. It argues that humanity's reluctance to acknowledge animal speech stems from intellectual arrogance and rigid dogma rather than a lack of evidence. Claiming that the human vocabulary of hundreds of thousands of words rests on a tiny foundation of just two dozen core phonetic sounds, the text points out that animals utilize nearly half that number of vocal elements. The book closes by asserting that recognizing speech and reason in other species does not demean humanity, but rather restores human beings to their proper place within a shared, interconnected natural world.

How It Unfolds

The problem of interpretation The inquiry opens by establishing that animal sounds must be decoded by observing physical reactions alongside vocal utterances, using the exact same methods one would use to learn an unfamiliar human dialect.

Surrender and submission Observations of captive monkeys reveal specific physical and vocal signals of capitulation, such as pressing the side of the head to the floor, extending the tongue, and emitting a mournful, interrogative cry when threatened or submissive.

Acoustic tests with the phonograph By recording vocalizations onto wax cylinders and playing them back to animals, the research confirms that monkeys recognize recorded sounds, while reversing the cylinders proves their calls consist of compound phonetic elements rather than simple noise.

Mirror experiments and cognitive limits Subjecting various monkeys to mirrors shows a wide range of intellect and personality; some reach behind the glass to locate the hidden companion, others kiss the reflection in silence, while timid subjects retreat in fear.

The continuum of reason The argument addresses the philosophical divide between instinct and intellect, claiming that all mammals utilize the same basic processes of reason to connect cause and effect, differing from human thought only in scope and complexity.

A challenge to human pride The work concludes by attacking the theological and cultural vanity that keeps humans from admitting that lower animals speak, maintaining that speech evolved alongside vocal organs to serve a universal desire for mental expression.

The People

R. L. Garner The author and primary investigator, who approaches his subjects with a mixture of patient empirical curiosity and intense emotional affection. He seeks to prove that animal vocalizations are structured languages, using phonographic recordings to validate his observations while advocating for a more compassionate understanding of non-human intelligence.

Mickie A robust, good-natured Capuchin monkey boarded at Central Park, who forms a close personal friendship with the author. Though generally taciturn except when desiring food or drink, his dominant personality drives the social dynamics within his cage.

Nemo A tiny, diplomatic Capuchin belonging to a private owner, characterized by his shy nature and cunning devotion to Mickie. He constantly imitates Mickie's actions—even biting the author's fingers out of perceived duty—and displays a gentle, solemn affection when caressing his own reflection in a mirror.

Nellie A female monkey who briefly escapes her cage, knocking over birdcages in a panic. Though terrified by the chaos, she is later rehabilitated in the author's apartment with toys and treats, allowing him to record her voice on the phonograph despite her lingering suspicions.

McGinty An inquisitive monkey who obsessively investigates mirrors, reaching his hands behind the glass, pecking at the surface, and uttering perplexity sounds whenever he fails to locate the animal hiding on the back.

In Its Own Voice

"He turned his bright little eyes pleadingly upon her as if to ask for pity."

When describing a small monkey shot in an East African forest, the text emphasizes the deep, emotional appeal animal distress makes upon human sympathy.

"Indeed, I have thought that our emotions and sensations may be like the diatonic scale in music..."

In reflecting upon the nature of tone and feeling, the author compares human sensitivity to a finely tuned instrument that naturally responds to the emotional cries of animals.

"If man could disabuse his mind of that contempt for things below his plane of life, and hush the siren voice of self-conceit, his better senses might be touched by the eloquence of truth."

Here the narrative directly confronts human vanity, arguing that intellectual arrogance prevents people from recognizing the evident intelligence of other species.

What It's Really About

Beneath its detailed accounts of cage behavior and phonograph tests, the work is an assault on human exceptionalism. It argues that key psychological traits—reason, sympathy, memory, and language—are not exclusive gifts bestowed solely upon humanity, but shared evolutionary tools distributed across the animal kingdom. The text exposes how human pride and traditional dogmas create artificial divides between species. By showing that animal cries carry distinct meanings and complex phonetic structures, it asks the reader to rethink the ethical treatment of captive creatures. Ultimately, it presents a vision of nature where human speech is simply a highly expanded version of the primitive sounds uttered by simpler forms of life.

Why Read It Today

This work offers a fascinating window into late nineteenth-century scientific curiosity, written at the exact moment when sound-recording technology was first applied to the natural world. Readers interested in early evolutionary theory, animal cognition, and the history of science will appreciate its unique blend of Victorian natural philosophy and hands-on experimentation. The prose is clear, direct, and driven by an unmistakable affection for its subject matter.

Modern readers should be prepared for the attitudes of the era. The text reflects nineteenth-century practices that readers today will find uncomfortable, including keeping wild primates in solitary domestic confinement, threatening animals with rods to test submission, and referencing field hunts. Furthermore, the author's tendency to anthropomorphize his subjects—attributing human guilt, sycophancy, and diplomacy to cage behavior— highlights the boundaries of Victorian observational science. Yet despite these historical limitations, the book's core plea for empathy, its inventive use of the phonograph, and its unshakeable belief in the intelligence of animals remain remarkably compelling.