TikTokers say they've discovered the secret to predicting whether a couple will last or eventually breakup − and psychologists say they're actually onto something.

It's called the bird test, and it's the subject of research conducted by psychologist John Gottman of The Gottman Institute, an organization dedicated to investigating the psychology of relationships. Videos tagged #birdtest have accumulated more than 16 million views with users testing the theory on their significant others.

The test involves getting excited about something insignificant and seeing how your partner reacts. For instance, if you look out the window and exclaim, "Wow, that's a beautiful bird," does your partner look to see what you're interested in or do they ignore it and go about their business? Or worse: Do they lash out and dismiss your enthusiasm entirely?

Repeated reactions that involve ignoring or flat-out rejecting your attempts to connect, even over something small like a bird, doesn't bode well for the future of the relationship, the bird test posits.

Gary Brown, a licensed marriage and family therapist, says there's a lot of truth to it.

"The beauty of the bird test is, basically ... it's a bid to ask whoever you're with to turn towards you and engage with you and show interest in something that you're interested in, versus what (Gottman) calls turning away," he says.

Is the bird test reliable?

The purpose of the bird test is to see how often your partner picks up on bids you offer them in your relationship. Brown describes a bid as "a request to engage and to connect with the other, no matter what the topic is," such as an invitation to look at a bird.

In his research, Gottman found couples who stayed together and reported feeling happy in their relationships turned toward each other about 86% of the time when presented a bid from their partner. Couples who broke up or felt unhappy in their relationships turned toward each other only about 33% of the time, according to The Gottman Institute's website.

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Bids may seem small, but they happen frequently, so it's important not to ignore them.

"Throughout the day, we're often making these bids right?" licensed psychotherapist Marni Feuerman says. "It's not unusual to say, 'Hey, do you want to have dinner now? Do you want to go on a walk? Oh, look at this cool Netflix show.' How is your partner responding and reacting?"

Several TikTokers have put their partners to the bird test, including former "Bachelorette" star Michelle Young, who practically jumped for joy when her significant other stopped to look out the window when she said she saw a cardinal. Gottman himself has endorsed the trend on TikTok as well.

What if the bird test goes wrong?

Don't panic if your partner fails a bird test.

Brown says that, if you're going to employ the bird test, make sure it's not during a time when your partner is occupied.

"If you're in a relationship and you are wanting to look at a bird, but it's the seventh game of the World Series for your partner, and your partner may say, 'I can't turn towards you now,' ... that doesn't mean that the relationship is doomed," Brown says.

Also, it's more important to see how your partner responds to you over time, so don't write them off if they fail a single bird test.

"Make those bids a few times over the course of a couple days," Feuerman says. "Look for the pattern. So, if consistently the partner ignores, doesn't respond, the bid isn't tuned into, then yes, I would say someone could reasonably discern 'I might have an issue here' or there might be a problem."

And if there is an issue, talk it out − and keep in mind no one is going to pass the bird test every time.

"People are going to miss bids on occasion, and so it's not about people getting worried or panicked that they're missing some, because you will. We all will," Feuerman says. "We're human."