If a person at a very young age falls into the wild forest and is lucky enough to be accepted into a pack of wolves or monkeys, then if people do not find him, in just a few years he will already be no different from an animal in his behavior. This is understandable, since a human baby is literally a "blank book", but how do adults who have fallen into the woods degrade into animals? And not somewhere in the jungle and not in the Middle Ages, but in a fairly developed country and only about 150 years ago.
In the 19th century, there were several cases in the United States when people observed a "half-human-half-animal". And it's not about the mythical yeti, but really about strongly degraded and completely wild people.
Medieval engraving depicting a feral man from Lincolnshire, England.
In 1871 in Burks County, Pennsylvania, a similar half-man frightened local residents with his terrible screams for several weeks. Articles about him appeared in various newspapers and even reached the New York Times:
The descriptions of this creature were equally frightening. They said that the hair from his head was so long that it covered his entire back, and his face was also very overgrown, which made him more like a monkey.
The locals trembled for a while from the sounds of his screams, but then they could not stand it and a well-armed crowd of men went to look for this half-man.
Nevertheless, the wild man was very dexterous and continued to run away from the hunters. They said that at the sound of his howling, the dogs also begin to howl and whine, and the half-man moves either on two legs, or even on all fours, while "with the speed of a wild tiger."
In one case, this savage was seen near a corral with horses and the horses were so frightened that they rushed to run away, and then refused to eat for a long time. "It seemed like they saw a demon."
On July 30, 1871, The New York Times reported that a half-man from Pennsylvania was spotted on the outskirts of the village and when people saw him they rushed at him in a crowd and finally caught him. And when he was examined, it turned out that he was still a man, only unusually neglected.
At the same time, he still retained the gift of speech and said that his name was Thomas Foley, that he was from Ireland and had previously worked as a lumberjack.
On October 17, 1868, two hunters from Williamstown, Massachusetts saw a similar wild man about 5 feet (152 cm) tall in the forest. His entire body was covered with red hair, a long red beard on his face, and his eyes were completely insane.
Later there was another message from the same area and probably about the same creature. It was said that this is a man, but extremely wild and dangerous to approach him.
And if the first case with a wild Irishman shows us that he was even able to retain speech and wore a loincloth, then in the second case the man was not only completely wild, but his whole body was overgrown with hair.
Was this a moment of real degradation to the level of an animal? Or maybe the hunters did not meet a person, but the same yeti?
In the American newspapers of the 19th century, you can find several more cases of observation of "wild people", but there, according to the results of investigations, it turned out that people most likely saw chimpanzees escaping from circuses or zoos.