Can a Chimpanzee Become Human?

Gua, the chimpanzee and her human brother, Donald, as reported on by the Santa Cruz Evening News, July 15, 1933.

We humans share 99% of our DNA with chimpanzees. Yet we’re so much smarter than them and can do so much more—like scroll through social feeds on smartphones and send men to the moon. But in 1931, one couple attempted to see how different the species would be if they were raised in the same way.

Associate Professor of Psychology Winthrop Kellogg of Indiana University, and his wife, Luella, adopted a seven-month-old baby female chimpanzee named Gua, and raised her alongside their own son, Donald, who was just two-and-a-half months older.

“Now no one, we hope, will be fool enough to suppose from reading a proposal of this sort that either of the writers has so far lost his senses as to presume that you can make a human being out of an animal,” the Kelloggs wrote in their book, The Ape and The Child.

Or could they?

Gua and Donald were short-lived siblings.

The couple mirrored Gua’s rearing with their son’s, down to the last detail. Gua was fed by bottle, bathed, clothed, cuddled, and pushed around in a stroller. Both were rewarded and scolded in the same way.

By the age of 16 months, Gua could understand fifty-eight words and phrases. When Donald was the same age, he had mastered a mere thirty-nine.

“She ate better with a spoon than Donald, was cleaner in her habits, could do more for herself without assistance, and, of course, could climb a tree when the boy could scarcely toddle!” one newspaper reported.

However, Donald pulled ahead in his development with his ability to speak. For all their efforts, the Kelloggs couldn’t make the chimp talk. They ended their experiment on March 28, 1932, when they had heard enough of Donald imitating Gua’s primate sounds.

By that time, Donald and his chimp sister had lived together as playmates and members of the Kellogg family for nine months.

Afterward, Gua was returned to the Anthropoid Experiment Station in Orange Park, Florida, where she was born.