The dating app conversation usually goes like this: "What are you looking for?" And people answer: "Someone who likes hiking, enjoys good wine, is into travel, appreciates dark humour."
Reasonable list. Except that sharing hobbies and tastes predicts almost nothing about whether two people will actually build a lasting relationship.
Meanwhile, the things that do predict lasting love — values alignment, compatible attachment styles, similar life stage priorities, capacity for direct communication — rarely come up in first-date conversation.
What the research actually shows
"Initial attraction is a poor predictor of relationship success. Value congruence, attachment compatibility, and communication patterns are far stronger predictors of long-term satisfaction and stability."
— Eastwick & Hunt, Relational Mate Value (2013)This meta-analysis examined decades of relationship research and found a consistent pattern: the things people focus on in initial attraction have remarkably weak associations with long-term relationship outcomes. The things that actually predict whether a relationship lasts, whether both people report satisfaction, and whether conflicts get resolved are notably different.
The four dimensions of real compatibility
Values: What you actually believe matters
Not hobbies or taste in movies — but the foundational beliefs about life, money, family, responsibility, spirituality, how you want to live. If one person believes children are essential and the other doesn't, no amount of shared love of Italian food resolves that. If one person prioritises financial security above all and the other prioritises experience, you're building on different ground. Values develop partly from childhood, which is why people raised in very different contexts sometimes struggle to bridge fundamental perspectives.
Life stage: Where you are in life
Someone in their 20s establishing career vs someone in their 40s with established life can work — but typically requires explicit conversation about what each person wants from the relationship. Someone who wants to be married within two years matching with someone who needs five more years solo will create constant friction. Life stage includes family planning timeline, geographic plans, whether you're looking to build or maintain. Misalignment here rarely resolves over time.
Attachment style: How you relate under stress
Secure-secure pairings are the most stable. Anxious-avoidant pairings are the most volatile — one person pursuing connection when distressed, the other withdrawing, creating a painful cycle. Two anxiously attached people can amplify each other's fears. Two avoidant people may never develop real intimacy. Secure partners can create corrective emotional experiences that help insecure partners develop earned security — but only if both are willing. This is why understanding your own and your partner's attachment style matters more than most people realise.
Communication: How you handle difficulty
Can you argue without contempt? Do you both attempt repair after conflict, or does one person shut down? Can you express needs directly without expecting the other person to read your mind? Do you listen to understand, or listen to respond? Communication style predicts whether relationships recover from rupture — and rupture is inevitable. So the ability to navigate difficulty well matters more than whether you have difficulty at all.
Matching built on real compatibility
40% values · 25% life stage · 20% attachment · 15% communication. LoveCertain matches on dimensions that research shows actually predict lasting relationships. £49. Full refund in 90 days if it doesn't work.
What hobbies and chemistry actually predict
This isn't to say that shared interests don't matter at all. They do — they provide reasons to spend time together, things to do, conversation threads. But research consistently finds that couples who love the same activities or have instant sexual chemistry are not significantly more likely to stay together or report satisfaction.
In fact, chemistry can sometimes be misleading. People are often most attracted to people who trigger their attachment wounds — that "spark" can be neurochemical recognition of a familiar pattern, not evidence of real compatibility. Someone with anxious attachment might feel intense chemistry with an avoidant partner (the familiar push-pull of their childhood). Someone with avoidant attachment might feel less spark with a securely attached person who actually wants to build intimacy.
The slow burn effect
Research on relationships that develop over time (rather than starting with intense attraction) shows they often become more satisfying and durable. Slow-burn relationships tend to be based more on appreciation, respect, and aligned life goals than on initial chemical attraction. Many people report that attraction deepened significantly as compatibility became apparent.
Why most dating apps get this backwards
Dating apps optimise for initial spark. They show photos, ask about interests, create conditions for matches based on attractiveness, proximity, and shared hobbies. This makes sense from a business model perspective — the initial spark keeps people swiping. But from a relationship outcome perspective, it's backwards.
If you wanted to actually match people who would build lasting relationships, you'd start with values alignment, assess attachment style, understand life stage priorities, and evaluate communication capacity. Then you'd check if there's physical attraction. The last step is the least important one — but it's the first step every swipe-based app takes.
This is why questionnaires matter
A genuine questionnaire that assesses values, attachment, life stage, and communication style takes longer than a photo swipe. But it gives you signal about actual compatibility. And matching on actual compatibility is the only reliable path to relationships that work.
The Certain Letter
Weekly insights on compatibility, attachment, and what research shows actually works. No fluff.
What to do with this information
If you're single, look for alignment on the four dimensions that matter. Ask potential partners about their values explicitly. Understand their family background and how it shaped them (which often relates to attachment). Be clear about your own life stage priorities and timeline. Pay attention to how they handle disagreement, not how fun they are at parties.
If you're in a relationship, examine your compatibility on these four dimensions. If you're aligned on three of the four, you have real material to work with. If you're misaligned on multiple dimensions — particularly values and life stage — that's useful information about the real work ahead.
Compatibility isn't a yes-or-no binary. But it's far more predictive than "do we like the same music" or "do we have crazy chemistry." And understanding what you're actually compatible on gives you both the realism to navigate difficulty and the hope that comes from knowing your partner actually fits your life.
