Are you worried that your lover might be losing interest in you? Well, try yawning. If s/he doesn't yawn back, your relationship might be in trouble. At least, that's if you believe a recent study on contagious yawning, which says that yawns are most contagious when they come from people you're closest to, reports NPR.

A 2011 study by researchers at the University of Pisa looked at 109 men and women from different countries and carefully observed their yawning patterns. They discovered that yawns are especially contagious when in the company of close family — parents, siblings, children. When one family member yawns, odds are the others are going to yawn too. Contagious yawning was slightly less common among mere friends, and rarer still among strangers or loose acquaintances.

The study also found that not all contagious yawns are created equal. The closer the relationship is, the faster the yawns move between senders and catchers. So, the time delay between yawns can potentially tell a lot about the closeness of a relationship. Are you BFFs, or just friends? Intimate lovers, or just friends with benefits?

This prompted science writer Sam Kean to ask a scandalous question in his newest book, "The Tale of the Dueling Neurosurgeons": What if you could tell if someone was falling out of love with you by measuring their yawn delay?

If the study's results are accurate, then the more someone is really into you, the shorter their average yawn delay ought to be. So if you really want to get scientific about it, here's an experiment you could try: Bring a stopwatch on all your dates, yawn, and start keeping track. If you notice a change in the yawn delay over time, perhaps it's a way of telling whether your partner is falling in or out of love with you.

Or not. Before jumping to any conclusions, keep in mind that such a test is purely speculative. While the experiment certainly raises some interesting questions, it might also reveal more about the tester than it does about the testee. Specifically, how much trust can possibly exist in a relationship that needs to be tested in this way?

It's a question worth asking before judging a partner's affection based upon their yawns. And anyway, how well can a date really be going if your partner is yawning all the time?

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