JUST how human could a chimpanzee become if one raised, feed and bathed just like a human child? Animal psychologists Winthrop Niles Kellogg and his wife Luella set out to answer this question in a bizarre experiment in the 1930s as they raised a chimp named Gua and their son Donald as “brother and sister”. Gua with baby Donald at the beginning of the wicked experiment in 1`931 Gua is tickled by the scientists during the experiment Donald being deliberately teased in a psychological experiment However, the couple got more than they bargained for when it was actually their son Donald who ended up becoming more ape than man. The experiment had to be cancelled as reportedly the tot started to make noises like a chimp and began to become more aggressive, even biting people. He grunted and barked like his “sister” when he wanted more food and would mimic her behaviours. Donald also began to move on all fours like the chimp – and the two would even wrestle like two wild animals. Seeing what was happening to their son, the Kelloggs terminated the experiment – and Gua was sent away, dying of pneumonia just a year later aged 3. And while not much more is known about Donald, he later killed himself aged just 43 in 1973. Most read in The Sun SUICIDE TRAGEDY Woman, 20, found dead in woods fourth in WhatsApp group to take own life BAG A BARGAIN I work for Home Bargains & here are the 3 secrets shoppers don't know about PAY RISE Millions could get £1,000 a year pay rise as PM plots National Living Wage hike NEV DEFENDS Gary Neville rows with Edwina Currie over 'ridiculous' Universal Credit claim DADDY'S GIRLS Joe Swash gushes over newborn daughter - who arrived on an 'expensive' day 'IT'S TERRIFYING' Woman held at Sarah Everard vigil says '50 cops' contacted her on Tinder On June 26, 1931, Kelloggs welcomed their new arrival, a baby chimpanzee called Gua, who they would raise alongside Donald. It was a bid to see whether environment would influence a chimp’s development – and how how human they could make it. The test was due to last five years – was abandoned just after nine months. Other theories as to why the test was axed claim it was cancelled as Gua was becoming too strong and may harm Donald. Gua was seven-and-a-half months old and Daniel was a smidgen older at 10 months when the trial began. And both infants were subjected to cruel tests such as being hit on the head with spoons, spun round in chairs, and being teased by their mum & dad. Gua and Donald play together on strollers Gua is fed just as a parent may feed a baby Kellogg was fascinated by children raised in the wild with little to no human help – and felt the best way to try and replicate that was bring a chimp into his home. “What would be the nature of the resulting individual who had matured … without clothing, without human language and without association with others of its kind?” he asked in his 1933 book, The Ape and the Child. He knew abandoning a human child in the wilderness was be morally reprehensible so instead, he opted to bring an infant animal into modern society. For the next nine months, 12 hours a day, seven days a week, Kellogg and his devoted wife – both comparative psychologists – conducted test after test on Donald and Gua. They were raised in the exact same way: they both wore baby onesies, made to sit in a high chair, slept in a bed and was kissed good night, though Gua was carted around in a small wagon. Our final concern is why the project ended when it did The Psychological Record Gua was taught the kind of things a fond parent would do to a baby girl. All the while, Kellogg ran a barrage of tests and started probing Gua and Donald’s “blood pressure, memory, body size, scribbling, reflexes, depth perception, vocalization, locomotion, reactions to tickling, strength, manual dexterity, problem solving, fears, equilibrium, play behavior, climbing, obedience, grasping, language comprehension, attention span, and others,” The Psychological Record author’s note. According to one report, the Kelloggs would tap Donald and Gua’s heads with spoons to hear the difference in the sound of their skulls and made loud noises to see who would react faster. They even tried to convince Gua not to eat soap bubbles by jamming a bar of the product into her mouth. Eerie footage of the experiment shows Gua and Donald being put in high chairs and being spun round and round until they start crying. They were also pushed to complete cruel tests in which they were put through a labyrinth and forced to get out while the perimeters changed around them. Psychological cinema register of Pennsylvania State CollegeSome tests included slamming a spoon on Gua head to hear the difference in the sound of her skull[/caption] The ape becomes distressed as she is spun round in a chair Gua is tied up before being blindfolded for another experiment For a while, Gua excelled in these drills compared to Donald; but after they both turned one, things began to change. Gua’s physical advantages were slowly eclipsed by Donald’s ability to formulate words and the doctors son realised they had hit the chimp’s limit of intelligence. Authors in The Psychological Record said Kelloggs’ experiment “probably succeeded better than any study before its time in demonstrating the limitations heredity placed on an organism regardless of environmental opportunities as well as the developmental gains that could be made in enriched environments”. But the experiment suddenly came to unexplained end, the publication said, adding: “Our final concern is why the project ended when it did. “We are told only that the study was terminated on March 28, 1932, when Gua was returned to the Orange Park primate colony through a gradual rehabilitating process. “But as for why, the Kelloggs, who are so specific on so many other points, leave the reader wondering.” There were rumours they were simply exhausted from nine months of non-stop parenting and scientific work. Gua showed no signs of learning human languages, but Donald, on the other hand, had began imitating her chimp noises. “In short, the language retardation in Donald may have brought an end to the study,” the The Psychological Record authors wrote. What’s more, OZY reports, Luella Kellogg became increasingly concerned Donald was becoming more chimp than human. Gua and Donald would wrestle in a way that looked more like-chimp and she had taught her older brother how to spy on people beneath doors. Donald began biting people and crawled like his sister. He grunted and barked like her when he wanted more food. Winthrop continued working at Florida State University where he took up research on bottle-nose dolphins and sonar until his retirement in 1963. He and wife Luella both died in the summer of 1972. The scientists using a gun to startle the cross-species siblings Psychological cinema register of Pennsylvania State CollegeDonald died in January 1973 and is believed to have taken his own life[/caption] We pay for your stories! Do you have a story for The Sun news desk? Email us at exclusive@the-sun.co.uk or call 02077824104. You can WhatsApp us on 07423 720 250. We pay for videos too. Click here to upload yours Click here to get The Sun newspaper delivered for FREE for the next six weeks.