The legendary orangutan Chantek is dead. Shantek is a tragedy. It was taught to study, studied experimentally, developed feelings with human beings, even went to college, and finally died in an iron cage. How did such a tragedy happen?
To put it simply, the story is that an orangutan raised by human beings has learned human language, can communicate with human beings, and even buys ice cream at an ice cream shop with money. Finally, he was sent back to the zoo because of an accidental attack on humans and died of depression.
What mechanism apes use to make those seemingly clever performances depends on very complicated and rigorous experimental design. Our psychological knowledge of animals and humans is still very limited, which makes the experimental design very difficult. For example. For an adult, if they really understand the word "ketchup", they can quickly identify all kinds of ketchup.
From an unexpected point of view, we often think that only human beings are advanced and rational creatures. Therefore, it is unexpected to see that apes are "smart". From a reasonable point of view, we all know that apes and humans are very close in evolution. Well, it's not that close, but much closer than cats and dogs. This makes people feel: Oh, no wonder.