Chemistry vs Compatibility: How Much of Each You Actually Need

Think of the five people you’ve had the most chemistry with in your whole life. Are you with any of them right now? Evan Marc Katz asked me that on my own show, and my answer took one word.

Chemistry vs Compatibility: The Short Answer

Chemistry is the pull you feel in the first ten minutes, physical, immediate and mostly out of your control. Compatibility is whether the two of you actually work on an ordinary Wednesday, over money, over kids, over how each of you behaves when you’re angry.

You need a baseline of chemistry and you need ALL of the compatibility, which is why Evan Marc Katz, sitting across from me on my own podcast, put the ratio at 70% attraction and 100% compatibility. Chemistry also runs on a clock, and he puts that clock at eighteen to thirty-six months. Compatibility is what you’re left holding when it runs out.

I’ve been making introductions since 1990. Around 40,000 people are privately registered with me and more than 1,400 couples have come out of it, so I’ve watched this question settle itself more times than most.

If the spark on your last date was a four out of ten, jump down to what to do on the next one.

What Chemistry Actually Is, and How Long It Lasts

Chemistry is physical, and most of the confusion comes from pretending otherwise. For a man especially, he has to be attracted or nothing happens.

It’s biological, and we call it the boing factor. My sister and I put it less delicately: we only have a shot with the guy who thinks we’re hot.

So I won’t tell you chemistry doesn’t matter, and neither will Evan Marc Katz, the dating coach who works with smart, strong, successful women who have everything but a partner. “Chemistry is a baseline from which you start,” he told me. “A good relationship 10, 20, 30 years down the road is not going to be a good relationship because of chemistry.”

Then the shelf life. He gave me the number loosely, so I’ll hand it over exactly as loosely.

According to the Wikipedia, Helen Fisher, the biological basis of love, chemistry, as we know it at the beginning of the relationship, has a half-life of about 18 to 36 months.

Evan Marc Katz

A rule of thumb, not a measured constant. His follow-up is the part with teeth. After the new car smell wears off, what are we left with?

Heidi Friedman, the lawyer who went on 104 dates and wrote a book about it, put it in a line. Butterflies are beautiful, and they go away, especially when hard things happen.

That’s a longer clock than the ninety-day drop everybody talks about, a different mechanism I’ve covered at the three-month mark. Infatuation, the honeymoon phase, new-relationship energy, it all runs on a timer. Nobody has built a marriage on a timer.

What Compatibility Actually Is, and Why “We Have So Much in Common” Isn’t It

Here’s where everybody goes wrong. They hear compatibility and picture things in common. Same faith, same politics, both love to travel. That’s a matching exercise, and it isn’t what keeps two people in a house for thirty years.

Alison Armstrong, who has run workshops on how men and women actually operate since 1995, gave me the best definition I’ve heard. Conflict has four sources, and those are the four places compatibility either exists or doesn’t.

• Values, the real ones your life is organized around, not the ones you preach.
• Verified needs, big benefit and big cost, like sleep or time alone.
• Then the two mischief makers, expectations and preferences, which in her words breed like bunny rabbits.

And then the line I’ve repeated to clients ever since. “We think because it says the same values in our profile that they’re going to be expressed the same way. No. Much deeper. What does it look like to live that way?” Two people can hold the IDENTICAL value and be entirely incompatible in how they practice it.

Money, kids, life goals and conflict style are where that gets decided, and none of it shows on a profile.

Her fix is the least romantic and most useful thing I know: negotiate the small protocols out loud rather than guess. She and her partner Dan agreed in advance that he answers nothing before 11am.

Evan’s version is shorter. Compatibility is how well the system works, how well the couple gets along. Is it easy? His diagnostic is one brutal question. Am I anxious all the time?

Orna and Matthew Walters, who coach singles for a living, put it in one sentence. People rush in with the feelings instead of evaluating the capacity of the other person to meet their needs.

Chemistry vs Compatibility: A Side-by-Side Comparison

Don’t read that as a scorecard. They’re two instruments measuring different things, and the mistake everybody makes is trusting the fast one because it’s louder. Intensity is not stability, and only one of them can be felt in ten minutes.

How Much of Each You Need: 70% Attraction, 100% Compatibility

Evan came back on the show a second time, and gave me the formula I’ve quoted ever since.

A good relationship is like putting a shoe in a foot. It’s a fit. It’s an alignment. But it is 70% attraction and 100% compatibility.

Evan Marc Katz

The asymmetry is the point. Seventy on attraction, not a hundred. You don’t need to be knocked sideways, you need enough that you want to touch him.

Then a hundred on compatibility. It’s a rule of thumb and he’s never dressed it up as a measurement, so don’t go scoring anybody out of a hundred. The asymmetry is what’s doing the work: you don’t need all of the attraction. You need all of the other thing.

He named the error everyone makes. “Most people go for the person they’re the most attracted to and then keep their fingers crossed that it works. And I pay more attention to, is it working?”

He also gave me three feelings to check after a first date. Attraction matters and fun matters, but comfort is the big one. Can I drop my guard, can I be silly.

That is emotional safety, and it isn’t soft. If a man doesn’t make you feel consistently safe, heard and understood, he says, there is zero point in continuing, no matter how cute or rich he is.

The Gut Check: Name the Five

This takes eight seconds, and Evan turned it on me live on air.

“Think about the five men that you’ve had the most chemistry with in your entire life. Are you with any of them right now?”

My answer was one word. Nope.

He said five men because he was talking to me. Do it with whoever you’ve dated. Name the five that made the room tilt, then count how many you built a life with. The people you had the most chemistry with are not the people you’re with. That isn’t a coincidence, it’s the pattern.

Dating and relationships almost don’t resemble each other, he says. It’s the audition versus performing the job, and plenty of people are terrific at auditioning and make poor partners. It’s a man’s job to be a great first date.

Why the Wrong People Feel Like Fireworks

If chemistry were a reliable signal, the five people you just named would have worked out. So what is it measuring?

Orna and Matthew Walters have the cleanest answer. We’re attracted to what is familiar, and we learn about love in our family of origin.

They correct clients on the grammar of it. Clients say, I keep attracting this kind of person. No. You are attracted to that kind of person. Matthew called his own version chasing rejection: when a woman was warm to him he’d think, what’s wrong with you, and sabotage it.

Gabriella Aratow, who runs a matchmaking practice in Aspen, calls it dating from your comfortable, uncomfortable zone. There was trauma in childhood, and what feels like home is a repetition of it.

I’m not standing outside this one. I used to date the charismatic guy, because my father was charismatic. Lots of personality. Loyalty, not so much. A little narcissistic tendency. It took me years to work out that the jolt I was reading as destiny was recognition.

A spark is not evidence that this person is good for you. It’s evidence that this person is FAMILIAR.

Alison Armstrong isn’t anti-chemistry, she’s anti too much chemistry, because too much of it from either side brings out the worstness. At that level you interact object to object, and to get heart to heart you have to check whether she cares what you need. You can’t check that while your ears are ringing.

If any of that is uncomfortably recognisable, I’ve written on whether your picker is broken, and on why love at first sight is a foolish way to find the one.

What to Do on the Next Date When the Spark Was a Four

This is the question you came with. Here’s my answer.

First, do you go back out at all? Here’s where my guest and I don’t agree, and I’m leaving it in.

My position is you get out on date two, and then date three, where the bonding starts. My rule has an end point. If you aren’t feeling it by the end of the third date, it’s probably a friendship. But DON’T ghost him. Keep the friend.

I also have a test he doesn’t. Men don’t tend to develop attraction over time. Women can. Ask a room of women whether they’ve ever met a man they weren’t attracted to, got to know him, and watched him quietly become adorable, and nearly every hand goes up. Ask a room of men and almost none do.

So my one-date test: is she more attracted to him at the end of the evening than at the beginning? Alison Armstrong has a name for that slow business of a man becoming attractive as you learn who he is. The Adam Sandler Effect. Her phrase, mind you, not industry vocabulary.

Where we actually stand is narrower than it sounds. He says a six can go to a nine. I say three dates, then it’s a friendship. The argument isn’t whether there’s a cutoff. It’s where the cutoff sits, and who gets to set it.

He closed more graciously than I’d have managed. If you agree with Julie, he said, take her advice, she’s really good at what she does.

So you’re going. Now the useful part.

Chemistry has a source, which means it has a dial.

That’s Alison Armstrong’s insight. The source is a perception of strength. Too much chemistry, go looking for weakness. Not enough, go looking for strength, which means hunting for the thing this person is genuinely formidable at.

The second fix is the venue rather than the person. Hunt Ethridge, a dating coach who explains men to women for a living, hears the identical complaint from both sides. His men ask how do I get chemistry. His women ask why aren’t these guys bringing chemistry. Nobody can BRING chemistry, he says, because it’s an interaction between two people. What you can do is set the stage for it to find you.

Dinner is the WORST possible stage. Men tend to sit side by side rather than face to face, and a lot of them read a steady stare as a challenge, while women use eye contact to show they’re present. So you’ve sat him across from a woman staring straight at him for two hours, and wondered why he went flat.

We’re also using logical questions and expecting an emotional result. What do you do for work has never produced a feeling. He takes dates to shoot pool instead, to see how they handle competition, how they handle losing, and how they treat the staff.

My own evidence that going back works. I once introduced two contemporaries, each of whom privately believed they ought to be dating someone younger. The date was at his country club and the gate needed her surname. He heard it, decided she’d look too old for him, and nearly killed it there. It happened anyway, because he knows you don’t back out of a date I’ve made. It went beautifully, and he asked to see her again.

Chemistry and Compatibility After 50

Everything above applies at any age. This part is for my own clients, mostly in their fifties and sixties, and it changes the arithmetic.

Two things dominate what people over fifty screen on, and they’re the two that predict almost NOTHING. Age and height. Evan can’t think of two things that matter less for long-term compatibility. What’s the difference between forty-seven and fifty-one? Nothing much.

So I cheat. I no longer reveal age on profiles, ever, and I stopped revealing height, because I’m just over it. Two people now meet each other instead of meeting each other’s numbers.

Gabriella Aratow said something in passing I’ve thought about ever since. As we age, a great deal of what being a good couple consists of is talking over dinner. Twenty years of it.

Which is why some of my best work starts as a friendship. Alison is right that turning a friendship into a romance is far easier than the reverse.

I once had a man freshly out of a divorce, deer in the headlights, and a woman who wasn’t ready either. Neither of you is ready for dating, I told them, you’re both hikers, you should know each other. Six months later they were dating, and a year after that they sent me a photograph from the house they’d bought in Michigan. More on that stage in dating over 60.

What Compatibility Is Not: Settling, and the Clone Problem

Two objections come up every time. The first is settling. Heidi Friedman was firm: don’t settle, and when you’re settling you don’t need it explained, it’s a feeling.

Then I make her define it, because women in my office use that word for two different things. Settling for Heidi meant a man who couldn’t be supportive, wasn’t honest and wasn’t family oriented. Other women tell me they’re settling because he isn’t as tall as she wanted.

One of those is a compromise on character. The other is a compromise on packaging, and only one of them will cost you your life.

The sorting tool is the three things you’d rather stay single forever than live without, and I run that exercise properly in loving yourself first. Go and do it, then come back and look at what you wrote.

The second objection is the opposite one and it’s fair. Doesn’t compatibility just mean finding your own clone? No. Evan’s phrase, which I’ve borrowed for years: he’s looking for his complement, not his clone.

Two ninety-fifth-percentile achievers matched on paper are very similar, often both in masculine energy, and it looks wonderful without working. He’s lived it. I once set him up with a woman who’d been to Harvard and spoke nine languages. What she lacked, and what his wife Bridget has, was warmth.

One man in my database went through 226 introductions before we found the one he’s still with. Years of chasing a spark instead of a fit. If that’s you, or if the phrase he’s a nice guy, but… has come out of your mouth lately, that’s the conversation to have.

Chemistry or compatibility was never the real question, because you don’t get to pick one. Get to a seventy on attraction, insist on a hundred on the fit, and go on the second date.

If you’d rather have me hunting that fit than do it alone on an app, get privately registered with me. A current profile and current photos is all it takes. Here’s how it works, from free through to VIP.

FAQs About Chemistry and Compatibility

julieferman.com · Julie@JulieFerman.com · 805-371-9557