In China, younger people are beginning to use wo ai ni (“I love you”)—something largely unheard of among older generations. “We said, Wo xihuan ni (‘I like you’),” the psychology professor Kaiping Peng told the journalist Roseann Lake, recalling his dating days during Mao’s Cultural Revolution. Until recently, “you just showed love through holding hands, kissing, or maybe writing or doing something nice—but you never said it.”

Here’s how distinct America’s situation is: In 2014, four Chinese researchers devoted a study to how the use of “I love you” had become a “daily phenomenon” in the States—directed even at pets and Facebook friends, and deployed for purposes ranging from apologizing to ending phone calls. Their goal was to help teachers in other countries explain the phrase to perplexed students learning English as a foreign language. “In our own experience, as teachers of English in China, we often try to avoid the explanation and practice of the locution I love you even though it appears in the textbook we are teaching,” they wrote. “We do not want to embarrass ourselves or our students.”

Some of the most insightful research on this topic has been conducted by Elisabeth Gareis and Richard Wilkins, both professors of communication at Baruch College. In a 2006 study based on an online survey of American and international students in the United States, Gareis and Wilkins found that relative to American students, international students reported less frequent declarations of “I love you” between romantic partners and from parents to children. Most respondents whose native language was not English said they used the English words ‘‘I love you’’ more often than the equivalent expression in their native language.

Gareis and Wilkins invited respondents to elaborate on how they thought about the phrase. Here’s what one Chinese-American woman wrote:

Every time when I go back home, my father always go to kitchen and asks me what I want to eat. He doesn’t say anything but make food for me quietly. It is very touching every time when I see my father does it. Love doesn’t have to be express verbally. … In China, men are always the heads of the families. The women were taught to obey their father, husband and son. Therefore, men are very dominating. In order to show men’s power, they don’t say ‘‘I love you’’ easily because it is considered emotional when they say it.

A Syrian-American man:

‘‘I love you’’ is a more serious and committing term in other cultures. Middle eastern girls I know who hear that from a guy automatically think marriage.

A Polish woman:

I know that if I would tell my parents straightforward that I love them they would not feel comfortable, same thing with my sister. We [Polish people] know we love each other but we don’t say it straight to somebody’s face if it is not our husband or wife. … I tell my son every day that I love him and he tells me the same thing. He was born here [in the United States] and I think it is easier for him and for me to use English ‘‘I love you’’ than if I would have to tell him in Polish. I don’t know how to explain this. I do mean real love when I tell him this, but it sounds different if I think about it in Polish. Maybe the way I was brought up has an influence.

A Colombian-American man (contradicting Juan Pablo, I should add):

It’s something that Latin people don’t really hold back on verbally. The word [“love"] is sometimes thrown around like a love struck teenager.

A Hungarian woman from Romania:

[Saying “I love you”] shows the weakness of the person who couldn’t control herself/himself and had to burst out. … My partner is American who feels the urge of declaring his love to me verbally and nonverbally way too often. And he is hurt by my reaction or lack of response. It took me four years, but I learned that it is important to him, so I let him say it, and I say it back, surprisingly easily. English is not my first, second or third language, saying ‘‘I love you’’ means nothing to me. I wouldn’t dare say it in Hungarian to anyone. … I must say things are changing lately. For 30 years I only heard on TV anybody saying ‘‘I love you.’’ … Since I’ve been studying in the US, my father started to write me text messages on my cell phone ending in ‘‘I love you.’’ My Mom expresses the same in the end of her e-mails. It’s a huge step in my family and for my culture. They still don’t say it to my sister, who lives in the same city [abroad].

So what explains all this variation? The Chinese researchers who studied the ubiquity of “I love you” in American English cited the anthropologist Edward Hall’s theory of “low-context” and “high-context” cultures, where the style of communication reflects a low or high level of common experiences. If the level of shared cultural context is high, much can be left implicit or unsaid. To generalize: A relatively young, individualistic, demographically diverse country like the United States is low-context; an older, collectivist, more demographically homogeneous country like China is high-context.