A psychological experiment in the 1930s ended in heartbreak after a 10-month-old baby was forced to grow up alongside a chimpanzee.
Researchers Winthrop Niles Kellogg and his wife, Luella took part in an unconventional experiment where they raised their son, Donald, alongside a 7.5-month-old chimpanzee named Gua.
The experiment, which sought to explore the effects of the environment on development, ultimately had devastating consequences, per Time Magazine.
The Kelloggs treated Donald and Gua as siblings, dressing them in baby clothes, feeding them in high chairs, and putting them to bed with a goodnight kiss.
Winthrop documented his rationale in his book The Ape and the Child, writing: “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?”
For nine months, the couple subjected both Donald and Gua to a series of tests, reportedly for hours each day.
Some of these tests included spinning the two children in chairs until they cried.
As Theodore Dumas later explained in Adult Health and Early Life Adversity: Behind the Curtains of Maternal Care Research: “The basic question was, is a chimp a chimp because it has chimp genes or because it is raised by other chimpanzees?
"Thus, if baby Gua grew up to be very chimp-like in a human household, then genes win. However, if baby Gua grew up to be more human than chimp, then environment wins. As such, Gua was treated like Donald’s sister and underwent the same bathing, dressing, and feeding processes.”
Initially intended to last five years, the experiment was cut short after only nine months when the Kelloggs observed troubling behaviors in Donald.
He began grunting for food, wrestling with Gua, and even biting.
Another theory, however, posits that the parents halted the experiment after fearing for Donald’s safety as Gua’s strength increased with age.
The aftermath for both Donald and Gua was nothing short of heartbreaking.
After the experiment ended, Gua was sent away from what had become a loving family environment to a “relatively barren cage” with other chimpanzees.
Dumas described the devastating impact on Gua: “This was the second time she was stripped from her ‘mother/caregiver’ and she went from a warm affectionate family life to a relatively barren cage with other strange and not so well-behaved chimps.
"She died less than a year later, circa her third birthday, of a broken heart (the official cause of death was determined to be pneumonia).”
Donald’s fate was equally heartbreaking. After the experiment ended, he grew up and pursued a medical career but tragically died by suicide in 1973 at the age of 43, just a year after his parents had passed away.
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