Want to date someone much hotter than you? Become friends first.

Ever notice how some couples seem perfectly matched on the attractiveness scale—here’s looking at you, Brad and Angelina—while others are a bit mismatched in the looks department?

Well, according to new research, there’s a reason for these couplings: Men and women are more likely to match with someone at their same “hotness” level if they start dating soon after meeting. If couples are friends first, however—or have simply known each other for awhile—they are more likely to be mismatched when it comes to physical attractiveness.

In other words, time really can make a person more attractive. That conclusion seems fairly logical, but it’s pretty interesting how often this concept appears to play out in the real world.

The study

To study how time affects who people choose to date, researchers from the University of Texas at Austin and Northwestern University looked at 167 couples—67 of which were dating and 100 of which were married. Each couple was asked to complete a questionnaire asking how long they had known each other, how long they had been romantic, and whether or not they were friends before becoming romantic.

The results were split. Forty-one percent of couples indicated hey had not been friends before dating, 40 percent indicated they had been friends first, and not surprisingly, 19 percent disagreed on whether or not they had been friends first. Ah, love.

The couples were also interviewed on camera in a lab, where they were asked to discuss how much they had changed since the beginning of their relationship.

The videos allowed researchers adept in “coding” physical attractiveness to rate the couples’ looks (for science). Some coders saw the couples together and gave each partner an attractiveness score; other coders rated only one person at a time, while the person’s partner was covered on the screen. This was done so the hotness of one parter didn’t influence the apparent hotness of the other.

The results

Turns out, “Couple members were less likely to be matched for attractiveness if they had been friends before they started dating,” the researchers reveal in the study. And vice versa.

In other words, couples who met and began dating shortly thereafter were considered comparable in the looks department. Couples who were friends for a period of time first—at least eight or nine months—were less likely to match on looks. This trend held true throughout the experiment.

The results help explain a common phenomenon—and a favorite storyline in Hollywood—in which you wake up and suddenly find yourself in love with your best friend. (Was Jake always this hot? No, he wasn’t, actually—you just passed the nine-month-getting-to-know-you threshold.)

Interestingly, none of these factors made a difference in relationship satisfaction. “Matched couples were no more likely to be satisfied with their relationships than mismatched couples,” say the researchers.

So even though couples who started dating soon after meeting were more likely to match based on attractiveness, the comparability didn’t effect their long term happiness—and neither did being friends first.

Why care at all, then, since it’s clearly a crapshoot? Well, let’s consider online dating, a medium in which looks are judged quickly and harshly. If this study teaches us anything, it’s that getting to know a person whose appearance may not immediately hook you can be worth it—and lead to a successful, happy relationship. Even if two people appear mismatched on the outside, they may be perfect matches inside.

Yes, that’s right—swiping left or right too fast could mean missing out on a future husband or wife.

As the researchers explain it, “In contexts that allow people to develop divergent perceptions about each other’s positive and negative idiosyncrasies, the traditional trappings of market forces fall away, permitting individuals to seek mates on a more level playing field.”

Taryn Hillin is Fusion’s love and sex writer, with a large focus on the science of relationships. She also loves dogs, Bourbon barrel-aged beers and popcorn — not necessarily in that order.