“We didn’t say ‘I love you,’” said Dr. Kaiping Peng, Associate Professor of Psychology Emeritus at the University of California at Berkeley. I’d ventured over to his China office on the campus of Beijing’s mighty Tsinghua University to talk to him about the romantic prospects of China’s rising fleets of well-educated, unmarried Chinese known as shengnü, or “leftover women,” but our conversation quickly took a historical detour. Though these days Peng wears Diesel jeans and spends his time jetting between Berkeley and Beijing, when he was a young, love-struck student during the Cultural Revolution things were different. “We said, ‘wo xihuan ni,’ (‘I like you’),” to express our deepest romantic feelings. Only in the more educated classes, where partners spoke English, were “I love you’s,” ever exchanged—and never in Chinese. “‘Wo ai ni,’ or the Chinese equivalent of ‘I love you,’ is a thing of the last thirty years,” he told me. “Before then, you just showed love through holding hands, kissing, or maybe writing or doing something nice—but you never said it.”

This was hard for me to get my head around. “I love you,” is probably about the third phrase Chinese students learn in English class after “hello” and “nice to meet you.” In China, I’ve seen it on everything from notebooks to bed sheets, from wall stickers to breakfast treats. My dentist once gave me a promotional keychain that said “I love you” on it after I had a cleaning. Yet, never having been privy to a Chinese world of close romantic attachment (things never did work out with my dentist), I had naively assumed that “wo ai ni” was used much like its English equivalent.

“No,” Guang Lu, a thirty-one-year-old investment banker with a strong affinity for Shakespeare, tells me. “The newness of those words still makes them very difficult for us to say.”

Could the reason for that be chemical?

Beginning in June 2010, with funding from a grant issued by the Chinese Ministry of Science and Technology, a team of scientists began to look at Chinese brains. The team was comprised of Dr. Arthur Aron, a psychologist at Stony Brook University; Dr. Lucy Brown, a Clinical Professor of Neurology at Albert Einstein College of Medicine; Dr. Xuchu Weng of the Department of Psychology and Neuroscience at the Chinese Academy of Sciences in Beijing, and Dr. Xiaomeng Xu, now Assistant Professor of Psychology at Idaho State University. By the time their study was over in August 2012, they would revolutionize the understanding of the Chinese brain and its relation to romance. Their work began in Beijing, where they recruited eighteen Chinese college students who reported being “deeply in love.” The students, who had been in relationships for an average of seven months, were put into a functional Magnetic Resonance Imaging (fMRI) machine at the Beijing MRI Center for Brain Research and shown a sequence of pictures for thirty seconds at a time. These included pictures of neutral, familiar acquaintances as a control, followed by a smiling picture of their sweetheart.

When viewing a headshot of their special someone, all of the participants showed vibrant activity in the dopamine-rewards system of the brain known as the ventral tegmental area, or VTA. Previous neurological studies have shown that this is a completely normal brain response; when a person falls in love, the VTA, as well as another nearby part of the brain—the caudate—is active. Stimulation of the VTA generally is associated with a cocaine high, the high a person might feel after winning a large sum of money, or with the “can’t think, can’t eat, can’t sleep” headiness of new love.

To control for cross-cultural differences, the team compared the brain scans of their Chinese student subjects with brain scans of American university students (of non-Chinese ancestry) who also reported being “intensely in love.” When comparing the American brains—scanned in an earlier, separate study—and the Chinese brain scans, the results were virtually indistinguishable. The areas and levels of activity in the rewards system of the brain were very similar across cultures. Until, upon taking a closer look at the scans with fMRI technology—which breaks the brain down into 76,000 minuscule voxels, or cubes—the researchers noticed a pattern of additional activity in the brains of Chinese participants.

“We weren’t sure of how to make sense of it when we saw it,” said Dr. Aron, who oversaw the study in tandem with Dr. Xuchu Weng. In addition to activity in the VTA, Chinese participants’ brains showed activity in the orbitofrontal region of the brain, which is involved with learning from negative feedback. In an attempt to make sense of what this activity could mean, the scientists asked ten questions designed to gauge where the thinking of each participant lay on a scale between “traditional” and “modern.” Traditional respondents were defined as those who were sympathetic to the view that “obeying authority and respecting the elderly are values that children should learn.” Modern respondents were those who leaned towards the view that “if married life is too painful, divorce is perhaps a way to solve the problem.” When comparing the answers with the brain scans, the scientists detected a pattern. Participants who answered most traditionally showed the most activity around an area of the brain also associated with learning from negative feedback, the right nucleus accumbens. The scientists’ discovery of this never-before-documented brain activity in response to romantic stimulus raised several new questions.

In interpreting the results of the scans, Dr. Aron is careful to point out that, when viewing pictures of their beloveds, the most traditional Chinese participants showed activity in the rewards area of the brain as strong as all other members of the group. “It’s not about a difference in the intensity of their love,” he stresses, “but in a complex pattern of brain activity which suggests that how they’re coping with the intensity of their love is different. There are feelings and thinking that are going on that are different.”

While it is impossible for a brain scan to explain why certain Chinese participants experienced a dash of negativity with their love high, the neuroscientists suspect that this neural response may be the byproduct of the way romantic love is perceived in Chinese culture. They reason that the additional neural activity may represent a different cultural understanding of romantic love—one that appears to cause Chinese to approach romance with greater caution, more mindful of external factors than Americans.

Well before a Communist regime required that an entire nation privilege revolution over romance, China had a long and tumultuous history with romantic love. While love-based marriages have existed in most of the developed world since the late eighteenth century—the time when, according to marriage historian Stephanie Coontz, choosing one’s own partner began to replace arranged marriage as a social ideal—the convention came more slowly to China. Arranged marriage was legal and widely practiced in China well into the late twentieth century and is not unheard of even today.

“Ancient Chinese literature is laden with tales of electrifying love at first sight and erotic bliss,” explains Stanford scholar of Chinese classics Haiyan Lee. But most Chinese love stories carry a similar moral: if one abides by the codes and prescriptions of the marriage process and doesn’t deviate from the structures of the familial network, the system will guarantee safe passage to happiness. But push the limits of passion a bit too far, Lee says, and one is bound to find oneself married to a rapturous but cataclysmically evil fox spirit.

Confucian ideals long discouraged romance between spouses by privileging relationships between men instead. As noted by the late scholar Francis Hsu in his book Under the Ancestors’ Shadow (Columbia University Press, 1948), Chinese families under Confucianism were gender hierarchies that subjugated women. The two strongest family relationships were between father and son and elder and younger brothers. The strength and order of a family was synonymous with the strength and order of the state. Any man who deviated from the system and appeared openly affectionate with his wife was seen as someone of weak character. As Coontz writes in her 2005 book, Marriage, a History: How Love Conquered Marriage, it also was not unheard of for a Chinese father to rape his son’s wife—free from fear of any legal retribution—in an attempt to disengage his son’s emotional attachment to her.

The late anthropologist Elisabeth Croll explained that Chinese relationship conventions changed overnight upon the Communist Party’s rise to power in 1949. Arranged marriages were outlawed (nominally, anyway), and young Chinese were encouraged, through several government campaigns, to find mates of their own. The campaigns often came with advice on how to find a spouse based on comradeship and shared revolutionary fervor. A 1964 article in The People’s Daily entitled “What Attitude Should a Husband take Towards his Wife?” warned that young people who married “on the impulse of the moment and on the basis of good looks and love at first sight, disregarding compatibility based on identical political ideas and mutual understanding” were doomed to “quarrel with each other constantly and suffer greatly.” By contrast, those who were not physically attractive but shared “revolutionary feelings” would experience a love “forever green.”

In August 2012, forty months after taking the brain scans, the neuroscientists called their eighteen Chinese participants again to see how “intensely in love” they still were. Six of the participants couldn’t be reached, but of the remaining dozen, half had broken up with their mate and half were still together. The neuroscientists then re-examined the original brain scans and tried to determine patterns that may have predicted the outcome of the relationships.

By comparing the original scans of each participant with their later reported levels of relationship happiness, the scientists made more discoveries. The most groundbreaking involved the identification of two areas of the brain which, when viewed during the early stages of romantic love, can be indicative of relationship longevity, satisfaction, and commitment.

“People who showed low activity in areas of the brain that have been associated with negative judgments of others were the ones who were still together,” says Dr. Lucy Brown. “Basically, the brain studies confirmed that suspending negative judgment of the other person is important for keeping a relationship together,” she explains. “Common sense tells us this is necessary, but the studies on Chinese participants really did show that it’s true, and suggest that it is key for all of us to keep relationships going, not just a minor aspect of successful relationships.”

The findings of this second part of the study are significant, Brown says, because they suggest that a couple’s initial feelings of attraction may indicate the course their relationship will take. “Psychologists sometimes say that when you’re in the early stages of romantic love, it’s so crazy, there’s no way of predicting how things will work out,” she says. “Others insist that there are things established early on that influence the outcome of the relationship, and at least on a neural level, that appears to be the case.”

Though the brains that Drs. Aron, Brown, and Xu examined in their neurological study in Beijing could very well belong to the children or grandchildren of Chinese who were of marriage age during times of “revolutionary” love, it’s worth noting that despite how far China has come since 1949—economically, socially, and in terms of personal freedom—the experience of romantic love in modern China appears still to be fraught with some cultural baggage, at least on a neural level.

Though the researchers acknowledge that their work is preliminary, they say that Chinese participants may engage the parts of their brain that cause them to “weigh the relationship more carefully, and take negative aspects into account more readily than Western participants.” Chinese cupid, in other words, strikes just as deftly as any other, but his arrow carries a distinctive sting. Is this sting the brain’s conditioned response to years of governance that has downplayed the individual relative to the group, to the extent that he or she feels guilty pursuing something as self-indulgent as romantic love? The notion is certainly worth considering.

Like Kaiping Peng, who as a young intellectual during the Cultural Revolution expressed his most romantic feelings in English, Guang Lu, the young financier with an affinity for Shakespeare, also mines the different possibilities for expressing his emotions. “For us, ‘I love you,’ is beautiful in its brevity, universality, and vagueness in another language,” he tells me, “but ‘wo ai ni,’ is still very unchartered territory.”