On June 26, 1931, psychologist Winthrop Kellogg and his wife welcomed a new arrival…….not a human, but a baby chimpanzee. The couple planned to raise the chimp named Gua alongside their own baby boy, Donald. The idea was to see how environment influenced development. Could a chimp grow up to behave like a human, or even think like one? For the next nine months, for 12 hours a day, 7 days a week, Kellogg and his wife conducted tests on Donald and Gua. They raised them in the exact same way while conducting a list of experiments that included blood pressure, memory, body size, reflexes, depth perception, vocalization, strength, problem solving, etc. For a while, Gua was actually excellent at the tests compared to Donald, but eventually the chimp hit a cognitive wall. No amount of training or nurturing could overcome the fact that Gua was still a chimpanzee. The experiment ended rather abruptly and mysteriously, with Gua being returned to the primate colony for gradual rehabilitation into animal life. It is suspected that while Gua showed no signs of learning human languages, Donald had begun imitating Gua’s chimp noises. In short, the language retardation in Donald may have brought an end to the study.