A、When they’re unable to control the person’s behavior. B、When the causes of the behavior are obvious. C、When the consequences o

M: One of the most common questions we ask about people’s behavior is why. Why did she say this? Why did he do that? Sometimes the reason is obvious. For example, someone is driving down the street, the light turns red, and they stop, why?
W: Because they have to, legally I mean.
M: Exactly! In this case the reason is obvious, so usually we don’t question it. But when the reason is not so obvious and especially when the behavior could have negative consequences, we’ll be more likely to feel a need to explain the cause of the behavior. Social psychologists have a term for this, for the process of explaining the causes of the behavior, it’s called “causal attribution”. And one theory suggests, there’s a pattern in the way we go about attributing causes to people’s behavior. According to this theory, there are two categories of reasons: internal factors and external factors. Again, Lisa, say you’re driving down the road and all of a sudden some guy turns into the lane right in front of you, and you have to slam on your brakes to avoid an accident. How do you react?
W: I’ll probably get very angry.
M: Because…
W: Well, he’s not paying attention, he’s a bad driver.
M: So you automatically attribute the driver’s behavior to an internal factor. He himself is to blame because he is careless.
W: So if I said it was because of heavy traffic or something, I’d be attributing his behavior to an external factor, something beyond his control.
M: Good. Now how do we usually explain our own negative behavior?
W: We blame external factors.
M: That’s right.
Questions 19 to 22 are based on the conversation you have just heard.
19. What is the main topic of the discussion?
20. According to the professor, when are people likely to try to explain someone else’s behavior?
21. What does the man use the example of a driver who stops at a red light to demonstrate?
22. According to the discussion, how do most people explain their own negative behavior?