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Exploring the Darker Side of Everything

Gua: The Chimp Who Was Raised as a Human and How it Went Wrong

Written by Laura Davies

In June 1931, just 10 months after the birth of their son Donald, psychologist Winthrop Kellogg and his wife Luella welcomed another baby into their home. Her name was Gua, and she was a 7 ½ month-old chimpanzee they intended to raise as a human child for 5 years.

The aim was to observe the extent that environment impacted development. If a chimp was raised as a human, would they behave like a human? Would Gua learn to wear shoes, eat with a spoon, sleep in a bed, use the toilet, or even speak? Most importantly, would she believe the Kelloggs were her parents and that Donald was her brother? Would she believe she was a human herself?

What followed was 9 months of the most rigorous and cruel testing you could imagine for two infants. They were spun until they cried, their hair was pulled, they were startled by gunshots and essentially tormented in the name of science. Kellogg’s published book on the subject entitled “The Ape and the Child” contains 27 uses of the words scream, screamed, or screaming. Hardly the work of a man who was raising two children in a loving home.


The Wild Children

Kellogg’s inspiration for the experiment were the stories of wild children. Kids who’d grown up with very limited human contact or sometimes none at all. In his book, Kellogg referred to three cases.

The first was “the wild boy of Aveyron” who was discovered living in a French forest in 1799. He was around 11 or 12, naked, covered in scars, and seemed to have survived by eating roots and berries. He couldn’t talk or communicate at all, and when his discoverers attempted to capture him, he legged it up a tree. Eventually, they managed to extract him from the forest and attempted to educate him, but their efforts were ultimately unsuccessful.

The second source of inspiration for Kellogg was Kasper Hauser. A German boy who’d grown up in solitary confinement. He claimed his cell had been 1 metre wide and 2 metres long, and he’d never seen his captor.

On his release, he could barely walk, speak, or use his hands. However, unlike the boy of Aveyron, after some education, he did learn to talk and write, and he told a fair few lies that brought his credibility into serious doubt. Nevertheless, Kellogg was fascinated by the story and how isolation from humans had affected his development.

His final inspiration came from “The Wolf Children of India”. These were two girls, Amala and Kamala, who arrived in the care of Joseph Amrito Lal Singh, an orphanage director, in 1920.

Singh told several lies about the girls. He wrote that they had long, sharp teeth; fixed joints that only allowed them to walk on all fours; and eyes that glowed blue at night. Why? Because Professor Robert M. Zingg paid him $500 in royalties for the publication of his diary and intended to make more through the co-authoring of a book, “Wolf-Children and Feral Man.”

Zingg was later dismissed from his academic post at the University of Denver for his part in publishing the blatant lies. However, Kellogg didn’t know this and took the case at face value.

He believed an unnamed man, who we now know to be Singh, was told that there were ghosts in the woods surrounding his village. When he and a companion went to investigate, they located a den. As they dug it out, three wolves emerged; two ran away, but the mother stayed to protect her young, and they killed her.

At the bottom of the den, they’d found a bundle of cubs and two human girls nestled together. He took them back to his orphanage, where he attempted to “civilize” them. However, it was a near impossible task. They ran about on all fours, howled, bit, scratched and ate raw meat just like the wolves, and neither could give up the habit of pouncing on live birds and small mammals and eating them. Tragically, both girls died young, Amala of a kidney infection in 1921 and Kamala of tuberculosis in 1929.

Nature or Nurture?

What each of these stories taught Kellogg was that it was possible that the environment in which a child is raised could have just as much of an impact as their genetics. The fact that none of the children could be educated also supported his belief that the early years of a child’s life were the most significant in establishing behaviour, or more poetically, “As the twig is bent, the tree’s inclined.”

However, none of the cases could really be used as evidence to support the theory, as, aside from the fact that they were mostly lies, no one knew whether the children had begun life with the ability to learn to talk or conform to social norms. Maybe each had been born with a disability, which, tragically, had led them to be abandoned or imprisoned.

Kellogg was desperate to test the theory, but as abandoning a human baby in the wilderness and observing them from afar was, just slightly, unethical, he came up with another plan. He could simply reverse the theory. If a human child raised in a wild environment becomes wild, would a wild animal raised in a human environment become human?

The Arrival of Gua

Kellogg found the chance to test his theory when his first son was born in August 1930, the perfect control subject with which to compare an animal born at around the same time. For the animal, Kellogg was provided with Gua. She was a 7 ½-month-old chimpanzee born at the Anthropoid Experiment Station in Florida.

Kellogg was initially frustrated that she wasn’t younger, but with a lack of any other options, he agreed, So, she was forcibly removed from her mother in June 1931. By this time, Kellogg’s son Donald was 10 months old, and the two would be raised together as brother and sister.

Naturally, people were wary about the ethics of his work. Some thought it was wrong to raise a human child with an ape sibling. Others felt Kellogg’s proposed 5-year experiment was too long for such a young child to be treated as a subject, and a few questioned the morality of removing Gua from her mother. Even Kellogg’s wife, Luella, had misgivings, as he wrote in the preface of his book,

“Indeed, the enthusiasm of one of us met with so much resistance from the other that it appeared likely we could never come to an agreement upon whether or not we should even attempt such an undertaking.”

Testing the Infants

Kellogg began his research by examining the physiological differences between Donald and Gua. Their blood pressure, body size, weight, temperature, and bone structure were all measured and monitored frequently. He even tapped them on their heads with a spoon to see if their skulls made a different sound. For reference, yes, they did. Donald’s skull produced a dull thud, while Gua’s made a harsher noise, like the crack of a mallet on a croquet ball. So it sounds like he just hit them gently then.

Kellogg also had a fascination with whether or not Donald and Gua would become dizzy in the same way. To study this, he used two methods. In the first, the babies were held by an experimentor and spun around 5 or 6 times. Then each baby was put down to see what happened. Gua would fall to her side and stagger for the same length of time as the experimentor, suggesting she had a similar dizzy response as the human. Donald would hold his breath, cry, and cling desperately to the experimentor, which made studying him difficult.

Knowing his son’s fear of being spun around, you’d think Kellogg would conclude his dizziness tests there. I mean, he’d already proven Gua could get as dizzy as a human, but no. He took his work up a notch by strapping each infant into a revolving high chair and spinning them ten times. 

He intended to observe and record the eye movements of each infant after they’d been spun to gauge dizziness. Instead, Donald would grip the chair, tense his abdominal muscles, and hold his breath until the chair stopped. At which point he’d yell and cry and be what Kellogg described as “much disturbed for some minutes”. This was doubly frustrating for him as the “activity of the subjects” led to a large margin of error in recording the eye movements.

Tormenting the Infants

Gua also had a fear, but not of being spun. She was incredibly afraid of toadstools. The Kelloggs discovered this by accident when they picked one up whilst playing outside. Gua started crying straight away, but they didn’t know it was because of the toadstool. That was until they offered it to her and she screamed and ran away. So, like normal parents, they decided to chase her with it. 

As Kellogg noted in his book, “she could be chased continuously in this manner, and would scream whenever her pursuer got too close. Defecations were frequent under such circumstances. When she was picked up by someone who secretly held a toadstool, and then shown it, she would either scramble down or bury her face in the arm of the carrier as if to escape the sight of the thing.”

That’s right, they discovered her greatest fear and then tormented her with it.

In another test, they’d send each infant through a labyrinth, forcing them to try to escape as they changed the parameters around them. To test their auditory reflexes, they placed both of their subjects in a high chair and made a loud noise behind them to see which one reacted first. What did they use to produce the noise? Something child-friendly like a xylophone, clap or bell? No, of course not. They used a revolver and shot it just a meter behind the infants’ heads.

Sometimes, they skipped the psychological torment and instead went straight for physical pain, all in the name of science, of course. Kellogg noted that when he pulled Donald’s hair, the child could be “induced to vocalize in a sort of whine or moan.” Gua, on the other hand, wouldn’t vocalize her pain and instead would try to push away her attacker’s hand even though this would “exaggerate the unpleasantness of her own sensations.”



Baby chimpanzees crave companionship and develop attachments, just like human babies and Gua was no different. Despite their cruelty, she treated the Kelloggs very much as her parents and showed signs of severe separation anxiety whenever they went out. A response Kellogg believed to have been heightened due to the forced separation of Gua and her mum.

On noticing her attachment, they decided to test it by running away from her faster than she could follow. This resulted in the following report,

“She seemed to become blind with fear and would utter a series of shrill vibrant screams which could sometimes be heard for a great distance. These would contain, as they progressed, more and more of the guttural element, until finally the windpipe would close entirely from a glottal cramp… Needless to say, protruding hair, urination, and defecation always accompanied an outburst of such”

On one occasion the Kelloggs went out while Gua and Donald were napping. They left a maid in charge but she was a relative stranger to Gua and unfortunately, the chimp woke up. According to the maid’s report, Gua started screaming and running from room to room, searching for one of her people. When she heard Donald cry she hammered on his door until she was let in and immediately calmed down.

The relationship between Gua and Donald was incredibly close. They would hug, kiss and hold hands. When he was placed in a high chair she’d climb up into it too and when she woke from her nap first, she’d peek under his door to see him. For the 9 months they spent together they were best friends and treated each other with more care than most siblings.



Throughout the length of the experiment, both Donald and Gua were subjected to rigorous daily tests. Every gap between meals and sleep was filled with measurements, photos, observations and tests. There was no part of their development that went unrecorded. Their toilet training progress, vocabulary recognition, first steps and every possible milestone were observed, recorded and charted. Kellogg even published pictures of his son, naked, in the same positions as Gua so we could see that, shockingly, the bodies of a chimp and a human are different.

The results of all of this meticulous work weren’t groundbreaking. Unsurprisingly a chimpanzee, that in the wild reaches puberty by 4 years old, developed motor skills much faster than the child. She could also learn to use a spoon to eat, a cup to drink and could tolerate human hygiene practices, like bath time. Again not exactly earth-shattering revelations.

In many aspects, she outpaced Donald until he began to communicate. Gua could use human gestures and facial expressions and learnt to respond to 95 words and phrases like “Kiss Donald” and “Show me your nose”. However, much to Kellogg’s disappointment, she never learnt to talk, even when they attempted to manually force her lips into the right shapes.

Donald on the other hand could talk. Worryingly though he didn’t progress past the 3 words he had when Gua arrived. Instead of learning new words, he began grunting like a chimp. Kellogg guessed this might have been partly due to the fact that the program of experiments wasn’t conducive to learning to speak and they’d had little socialisation with other children. As you might have guessed, there weren’t many parents willing to let their toddlers spend a huge amount of time playing with a chimp.

The End of the Experiment

The Kelloggs terminated the study after just 9 months on the 28th of March 1932. Winthrop’s reason for ending it over 4 years early was never explained beyond, “Gua, treated as a human child, behaved like a human child except when the structure of her body and brain prevented her. This being shown, the experiment was discontinued.”

Of course, there are a few theories.

Some believed that the couple were just exhausted from 9 months of parenting and experimenting. Others thought that Gua might’ve grown too strong, and the Kelloggs feared that she’d harm Donald. The final theory was that it was Donald’s lack of speech and excess of chimp noises that caused them to call it off. It seemed that rather than Gua becoming more human, their own child was becoming more chimp.

Gua was returned to Dr Yerkes and placed in a cage for experimentation by his wife, Ada. How she took the transition, from life as a toddler with two parents, a brother, a bed, toys and a garden to life as a lab animal wasn’t reported. However, in one of Kellogg’s studies he recorded her response to being locked in a box, which probably goes some way to describe her reaction.

“She was much upset by the confinement, would scream and bite at the bars, and threatened in some cases to injure herself.”

She died of pneumonia just a few months later.

What became of Donald? Well, he did learn to talk, as soon as the experiment ended, and he did quite well for himself. He became a doctor of psychiatry and got married. Tragically though, he killed himself at just 42 years old. Whether that was down to the cruelty and trauma he’d experienced as a child or something else, we’ll never know.


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