Picture two ordinary scenes.
In Mumbai, a Bollywood hero stands in the rain, professing his love with the kind of unfiltered, all-consuming intensity that would look almost deranged in a real living room. The film sells out. In Melbourne, a young couple argues — not because either of them has done anything wrong, but because one of them keeps buying surprise gifts and saying “I love you” three times a day, and the other can’t understand why that’s necessary when they already do the dishes without being asked.
Different continents, different conflicts, same underlying question: what actually counts as love, and why does it look so different depending on where you’re standing?
For a long time, psychology’s answer was cultural values — the old individualism-versus-collectivism story. Western cultures prize the self; Asian, Latin American, and Middle Eastern cultures prize the group. Case closed.
Except the data doesn’t cooperate. Repeatedly, cross-cultural studies have found that people in “individualistic” societies like the United States and Australia report more passionate love, more self-disclosure, and more active emotional investment in their relationships than people in “collectivistic” societies — the ones supposedly built around connection and belonging. That’s backwards. If collectivist cultures are the relationship-oriented ones, why are individualists the ones falling head over heels?
The answer isn’t about values at all. It’s about math — specifically, the math of how easy it is to lose someone.
The theory that resolves this puzzle is called relational mobility (Yuki & Schug, 2020; Thomson et al., 2018), and once you see it, you can’t unsee it in your own relationships.
Relational mobility describes how much freedom a society gives people to choose, and walk away from, their relationships. In high-mobility societies — North America, Western Europe, Australasia, Latin America — people meet new people constantly, relationships are voluntary, and if a friendship or romance stops working, you leave and find another one. It’s an open market.
In low-mobility societies — East Asia, Southeast Asia, the Middle East — relationships are far more fixed. You keep the same social circle for years, often for life. Family, community, and workplace ties are sticky, not swappable. You don’t audition new best friends the way you might in a large Western city; you work with the people you’re already connected to.
Here’s the twist: these two environments don’t just produce different relationship styles. They produce entirely different adaptive problems, and completely different tools for solving them — including apparently universal emotions like love.
In a high relational-mobility environment, your biggest relational risk is that someone better will come along and take your partner. Economists would call this a liquid market with lots of competing buyers. So what’s the adaptive move? You signal, loudly and unmistakably, that you are committed — so your partner doesn’t wander, and so rivals know the position is filled.
This is where a study by Yamada, Kito, and Yuki (2017) gets interesting. They found that passionate love — the all-consuming, can’t-think-about-anything-else kind — is more intensely felt in high-mobility societies, and that the intensity tracks how replaceable people perceive their relationships to be. Passionate love isn’t just an emotion that happens to you. Following economist Robert Frank’s classic theory of commitment (1988), it functions as a costly, hard-to-fake signal: it directs your attention and your helping behavior exclusively toward one partner, which is exactly the kind of signal a partner needs to feel secure when better options are, in principle, one swipe away.
A companion study on gift-giving (Komiya et al., 2019) found the same logic playing out in something as mundane as presents. Married couples in the United States — a high-mobility country with a comparatively high divorce rate — gave each other gifts more frequently than couples in Japan. And within Japan, people who had more varied social opportunities (more chances to meet new people) also gave more gifts. Gift-giving, like passionate declarations of love, is a proactive proof-of-commitment strategy for a world where partners can leave.
Flip the environment, and the whole logic inverts. In low-mobility societies, your partner isn’t going anywhere — and neither are you, easily. The risk isn’t abandonment; it’s being stuck in a low-quality relationship, or damaging your standing within a social network you can’t exit. So the adaptive strategy shifts from loud proof of commitment to quiet avoidance of harm: don’t rock the boat, don’t over-disclose, maintain harmony. Not because people there feel less deeply, but because the environment is rewarding an entirely different behavior.
This is the theory behind that Bollywood rain scene, too, if you want to push it further: in societies where relationships are otherwise fixed and constrained by family and community expectation, wildly passionate, autonomy-driven love in film and pop culture can function as escapism — a vicarious taste of a freedom of choice that the real social world doesn’t actually offer. The same theory that explains why Americans report more passionate love than Japanese couples also offers a lens on why passionate love is such compelling entertainment precisely in places where it’s hardest to enact.
(Curious how this plays out specifically in Bollywood? We wrote a whole piece on that.)
Relational mobility explains how much commitment-signaling a culture rewards. It doesn’t fully explain what form that signal takes — and this is where a second body of research fills the gap, and where a lot of real intercultural relationship friction actually lives.
Self-construal theory (Markus & Kitayama, 1991) is the foundational idea here. People raised in independent, individualist cultural contexts tend to construe themselves as separate, bounded agents whose traits and choices define them; commitment gets expressed through explicit, individual acts — saying it out loud, buying the gift, planning the surprise. People raised in interdependent contexts construe themselves more relationally — defined through their roles and connections to others; commitment gets expressed through attentiveness, anticipating needs, and quietly fulfilling one’s role, without needing to announce it.
Layer on affect valuation theory (Tsai, 2007) and the picture sharpens further. Tsai’s research shows that cultures don’t just differ in which emotions they value — they differ in the ideal intensity of positive emotion itself. Western, independent cultural contexts tend to idealize high-arousal positive states: excitement, enthusiasm, exuberance. East Asian, interdependent cultural contexts more often idealize low-arousal positive states: calm, contentment, peacefulness. Neither is “more positive” than the other — they’re different targets.
Put these two theories together and you get a strikingly precise explanation for exactly the kind of conflict in that Melbourne apartment. One partner expresses commitment through verbal enthusiasm and grand, explicit gestures — an independent, high-arousal script. The other expresses it through quiet, competent, anticipatory care — an interdependent, low-arousal script. Both are demonstrating real commitment. Neither is lying, withholding, or under-invested. They are simply running different cultural software for what “proof of love” is supposed to look like — and without a name for the mismatch, it’s easy for the demonstrative partner to read quiet care as coldness, and for the quiet partner to read repeated verbal reassurance-seeking as insecurity or performative excess.
It would be easy to file all this under “interesting trivia about love.” But the practical stakes are broader than romance:
For intercultural couples and families, simply having language for the mismatch — “we’re not incompatible, we’re running different commitment scripts” — tends to defuse a huge amount of unnecessary conflict. The fix usually isn’t for one partner to become the other; it’s for both to learn to recognize the other’s signal as sincere, even when it doesn’t match their own instinctive read of what love should look like.
For anyone living, working, or building relationships across cultures — expats, exchange students, international teams — the same logic extends past romance into friendship and even professional trust-building. Someone from a high-mobility background may read reserved, businesslike interactions as a lack of interest in becoming friends, when the actual local norm is “we don’t over-disclose until real trust is earned, because unlike where you’re from, we can’t just quietly drift apart if it goes badly.”
For anyone building products, brands, or messaging across markets, the same principle applies at a less personal level: what reads as sincere, trustworthy commitment in one cultural context (explicit, frequent, enthusiastic communication) can read as excessive or suspicious in another (where understated reliability is the trust signal), and vice versa.
Love, it turns out, isn’t one universal feeling wearing different cultural costumes. It’s an adaptive strategy that gets shaped by a very concrete, very measurable feature of your social environment: how easy it is, in practice, to lose the people you care about — and how loudly your culture has taught you that commitment needs to be proven once you have them.
That’s a more useful idea than it sounds. It means the next time someone’s way of showing they care looks nothing like your own, the right question probably isn’t “do they really love me?” It’s “what environment taught them that this is what love looks like?”