A、Causes of sleeplessness. B、Cross-cultural communication. C、Cultural psychology. D、Motivation and positive feelings. C讲座开头，讲话人做

I’m a psychology professor at the University of British Columbia. I specialize in cultural psychology examining similarities and differences between East Asians and North Americans. Our research team has been looking at cultural differences in self-enhancing motivations, how people have positive feelings towards not only themselves but things connected to themselves. For example, when you own something, you view it as more valuable than when you don’t own it. It’s called the “endowment effect”. The strength of that effect is stronger in Western cultures than in East Asian cultures. So we’ve been looking at other ways of seeing whether this motivation to view oneself positively is shaped by cultural experiences.
We’ve also started to look at how culture shapes sleep. We’re still in the exploratory stages of this project— although what’s noteworthy is that East Asians on average sleep about an hour and a half less each night than North Americans do. And it’s not a more efficient sleep, not like they’re compressing relatively more value out of their hours. Other studies have found that even infants in East Asia sleep about an hour less than European infants. So we’re trying to figure out how culture shapes the way you sleep.
Our experiment does not take place in a sleep lab. Instead we lend people motion-detecting watches and they wear them for a week at a time— whenever they’re not having a shower or swimming, they keep it on. These kinds of watches are used in sleep studies as a way of measuring how long people are sleeping, how efficient their sleep is, and whether they’re waking up in the night. Ideally I’d like to take this into a controlled lab environment. We’ll see where the research points us. We usually start off with the more affordable methods, and if everything looks promising, then it’ll justify trying to build a sleep lab and study sleep across cultures that way.
Why do we study sleep? Sleep is something that has really been an unexplored topic cross-culturally. I’m attracted to it because culture isn’t something that only shapes the way our minds operate; it shapes the way our bodies operate too, and sleep is at the intersection of those.
Questions 22 to 25 are based on the recording you have just heard.
22. What does the speaker mainly study?
23. What does the speaker say about North Americans?
24. How did the speaker conduct the sleep study?
25. What does the speaker say about research on sleep?