The Mirror Test
The Mirror Test Very young children cannot recognize themselves in a mirror; they usually achieve this milestone around 18 months of age. The ability to recognize oneself in the mirror is considered to be a key component of self-awareness and consciousness for humans. But what about animals? For many years, scientists have known that members of the great ape family could recognize themselves in mirrors. They measured this by the “mirror test,” which involved putting a colored mark on an ape’s body, and then showing the ape its reflection in a mirror. If the ape tried to remove the mark on its own body, the scientists knew that the ape was recognizing its reflection. Apes are close relatives of humans, but in recent years, scientists have discovered that other animals also pass the “mirror test.” Elephants and dolphins have shown signs of self-recognition. These, like apes, are highly intelligent animals. But in a more recent experiment, a type of fish called the cleaner fish tried to scrape a mark off its body when it saw itself in the mirror. This suggests that even less intelligent animals may possess more self-awareness than previously suspected. 16. What is the passage mainly about? (A) Stages of early childhood development (B) Research on animal cognition (C) Differences between apes, elephants, and dolphins (D) Recent experiments on fish 17. The word “milestone” in the first sentence is closest in meaning to (A) accomplishment (B) distance (C) weight (D) discovery 18. Why did scientists put colored marks on animals’ bodies? (A) It made it possible to track the animals’ movements. (B) It helped them determine whether the animals recognized themselves. (C) It made it easier to tell the animals apart. (D) It showed whether some animals can detect color differences. 19. According to the passage, all of the following are true about elephants EXCEPT: (A) They can recognize themselves in mirrors. (B) They are highly intelligent animals. (C) They possess qualities in common with apes. (D) They understand certain signs from other animals. 20. Why does the author mention cleaner fish? (A) To suggest that a wide range of animals may possess self-awareness (B) To imply that ocean animals are highly intelligent (C) To demonstrate a flaw in a recent experiment (D) To provide an example of an animal that does not recognize itself