The history of psychology is full of unusual studies and experiments that would hardly be justified or possible today. The reason is that many of these studies were based on experimentation with young children, adolescents or people with some kind of mental or psychiatric disorder, all of whom were unable to decide or understand the effects of the disorder.

One of these experiments was that of the chimpanzee Gua, conducted by psychologist W. N. Kellogg . It is an investigation on behaviour and learning in which Gua was raised for months within a family, with the intention of checking whether the chimpanzee could be educated like the rest of the children.

As father and daughter: the chimpanzee Gua and W. N. Kellogg

In the 1930s Winthrop N. Kellogg, a psychologist and professor at Columbia University, specialized in the processes of conditioning, learning and human behavior, set out to investigate the differences between animals and humans in learning and behavior .

To do this, Kellogg adopted a two-month-old female chimp and brought her into his home with the intention of educating her in the same way as he did his son Donald, who at that time was less than a year old. During several months, Kellog raised them as if they were brothers , dedicating the same attention, love and care to each of them with the aim of contemplating and analyzing the evolution and learning of both of them.

The animal chosen for the study was given in the name of Gua and, without her knowing it, its aim was to reveal at what point some kind of distinction between the processes and advances in learning between an animal and a human began.

The result: something unexpected

After nine months of living together, the results were not at all what Kellogg expected, since, in short, Gua ended up “humanizing” himself to the point of learning more quickly and effectively than his son , and the little one ended up developing chimpanzee-like behaviors such as trying everything with his mouth or emitting howls and grunts like Gua.

Such was the degree of learning of the little one that a great part of the idioms and habits that he had learned from Gua would remain intact throughout his life.

The product of this research was the work The ape and the child , published in 1931 and which was not exempt from criticism and controversy. In his text, Kellogg details each and every one of the learning activities and games he carried out with both of them, as well as the effects they had on the children.

As a consequence, the American psychologist received very tenacious and merciless criticism that accused him of having subjected his son and the animal to an experiment that would leave a mark on both of them for life. The impact of the criticism was felt by Kellogg, who eventually admitted that he had been wrong.

How did the baby-baby experiment go?

In the early days of the research, it focused on collecting data about the physical condition of both Gua and little Donald. Both Kellogg and his wife, accompanied by a group of researchers, began collecting data such as weight, blood pressure and reflexes, and then began with activities and tests related to learning .

Over the next nine months, Kellogg and his wife raised Gua just as they raised their son, as if they were brothers. They recorded the data on film and carefully described any and all changes or advances in each of the children.

The data obtained by Kellogg and his team focused on aspects such as memory, drawing ability, vocalization or language, manual dexterity, locomotion, problem solving, fear and dread reactions, obedience and even responsiveness to tickling.

What were the results?

During the time the study lasted, Kellogg observed how Gua developed a fascinating capacity to adapt to a human environment , to the point of taking orders and following guidelines much better than his “brother” Donald. Other of the many behaviors learned by Gua were related to the ability to ask for a person, give kisses to other people, and she even learned to eat by herself in the same way as humans or to bathe by herself.

On the other hand, Donald had one characteristic: he was a much better imitator. While Gua in the advanced student, who was able to discover before Donald the functions and utilities of the objects and showed a better understanding of the different games and activities they performed, the little human was only dedicated to imitate or reproduce what the chimpanzee did.

As a consequence, little Donald also began to imitate some of Gua’s gestures, behaviours and language, using grunts, snores and animal noises and experiencing a notable delay in language development and notable communication difficulties. This is one of the reasons why, despite Gua’s progress, Kellogg decided to stop the experiment after nine months of testing. After this time, he separated the two “brothers” and Gua was returned to the Orange Park Zoo, where she was removed and could not adapt, dying the following year.

As for Donald, he had reached the age of 19 months by the end of the experiment and yet was only able to express a small number of words, whereas any child of his age should have at least a repertoire of fifty and be able to start forming sentences and phrases. Fortunately, he later compensated for this disadvantage and even completed university studies.

What conclusions were drawn from this study?

Regarding the learning processes, Kellogg concluded that, at least during the infancy stage, children are highly influential and that in their first years of life their reasoning and intelligence skills may be comparable to those of an intelligence animal with characteristics comparable to those of a chimpanzee.

However, later these paths separate, with human beings being able to develop a much higher level of intelligence and skills.

As for the intellectual development of the chimpanzee, Kellogg’s methods may reflect that they, in the first months of life, have the capacity to develop a language analogous to human, although they are incapable of speech . In the same way, although they are skilled in making simple tools, there is a huge difference in the capacity of ideation between chimpanzees and humans.