Let’s be honest: Being single sucks sometimes. If you’re anything like me, it’s practically impossible to get through a day without being reminded of your unattached status. My Facebook wall is littered with pictures of happy couples and new babies. My partnered friends always seem to know “the perfect guy,” and I can’t even count how many times my family has asked if I’m “seeing anyone special these days.” It’s like there’s a flashing neon sign everywhere I look that screams: “You’re not getting any younger!”MORE: Are You Stuck in a Dating Rut?So when a site like eHarmony boasts that they match singles “based on 29 Dimensions® of Compatibility for lasting and fulfilling relationships,” signing up sounds pretty tempting. “It is possible,” eHarmony’s scientist, Gian C. Gonzaga, Ph.D., told The New York Times, “to empirically derive a matchmaking algorithm that predicts the relationship of a couple before they ever meet.”That’s a pretty bold claim, and eHarmony is not alone in making it. Numerous online dating sites now declare that they have mastered a scientific approach to matchmaking, boasting complex mathematics that will pair you with the perfect partner. But can they really do it? Is there a scientific way to assess whether two people will fall in love?If you ask professional matchmaker and love guru Matthew Hussey, the answer is yes—but mostly, no. We’ll explain.Though Hussey was one of the three “matchmakers” on NBC’s failed dating show “Ready for Love,” he cringes slightly at the title. “I’m not the guy who tells you what is right for you and tells you who to go for,” says Hussey, author of “Get the Guy: Learn the Secrets of the Male Mind to Find the Man You Want and the Love You Deserve.” Instead, he prefers to call himself a life coach. “I will give you the tools to be incredible, the best version of you that you can ever be.”As far as online dating sites go, his reaction is lukewarm. He’s not against them, per se. “If it gets you slightly closer, then, well, great,” he says. But Hussey finds it hard to believe that the online dating algorithms are really as good as the websites claim. “I think that the benefits of matching in those ways are wildly overstated, and that applying an algorithm to [love] is beyond difficult.”COLUMN: How to Find LoveSaying that one person is “right” for another using a set of traits is “a very arrogant notion,” Hussey continues. “I don’t think I can do that, and I don’t think anyone can really do that.”Scientists who have studied human relationships for years agree. “If you’re going to make scientific claims, act like a scientist—or don’t make scientific claims,” UCLA social psychology professor Benjamin Karney told LA Weekly. Karney and four other scientists published a scathing review of online dating in 2012, concluding “no compelling evidence supports matching sites’ claims that mathematical algorithms workthat they foster romantic outcomes that are superior to those fostered by other means of pairing partners.”The big problem with these algorithms is their reliance on personality tests. Hussey is skeptical that questionnaires can really cover all of the important components of lasting attraction. “It assumes that we know the nuances that get people attracted to each other,” he points out. “It also relies on people telling the truth in the questionnaires!”Hussey isn’t the only one who questions the validity of self-reported answers. A 2008 study of online daters found that many profiles contain blatant lies, even about the easiest of traits: Men lied more about their height, and women lied more about their weight. Scientists have even found that people are more likely to exaggerate their traits when they are specifically looking to find a date on the Internet.MORE: What You Can Learn From Speed DatingSometimes this occurs deliberately, but often, it doesn’t. The trouble with self-reported measures is that they assume people actually know what they are like, but often, we don’t. We’re not as good at judging our own personalities as other people are, for example. When we read a question such as “on a scale of 1 to 10, how nice are you?” no one wants to say “I’m a total jerk!” So they tend to respond as who they want to be, rather than how they really are.But perhaps an even bigger problem is that even when such tests are designed and administered by trained professionals, results can vary. Test-retest repeatability of 70 percent is considered good enough in the field, but clearly, that means that day-to-day, our results will be different. For reasons that aren’t exactly clear, some people’s responses change a lot while others are fairly consistent, and external factors like when and how the test is taken, how the questions are worded and even the instructions that are read beforehand can change how people respond.That’s not to say there isn’t a little science to finding a great relationship. Hussey has a four-prong formula of his own that provides the building blocks to lasting attraction. And while he hasn’t published any papers on his four components, decades of research support his theorem. His “Attraction Formula” isn’t an algorithm for finding the perfect guy—it’s a set of criteria that are found in healthy, happy, long-term relationships. Here’s the formula: Visual Chemistry + Perceived Value + Perceived Challenge + Connection = Love.MORE: What’s Your Love Language? • Visual Chemistry. “Looks play a part in everything,” says Hussey. “I can never argue that they don’t.” But he is quick to note that Visual Chemistry isn’t just about looks. “Looks create a reflex response,” he explains, “but the trap that people fall into is assuming that the reflex response is the deep level response.”A picture may be worth a thousand words, but animation, says Hussey, creates attraction. “When you’re with someone, and they’re living and breathing and joking and moving and thinking and gesturing, then you really know how attracted you can be to that person.” Scientific research supports his statement. Scientists have found that videos of people are rated more highly than photographs, suggesting that people are perceived as more attractive when they are active.As Karney and his colleagues explain, “encountering potential partners via online dating profiles reduces three-dimensional people to two-dimensional displays of information, and these displays fail to capture those experiential aspects of social interaction that are essential to evaluating one’s compatibility with potential partners.” This is a major flaw in online dating—just looking at a picture doesn’t give you a complete image, and you need the whole picture to know if there’s chemistry.MORE: Dating Advice Books: The Truth About What Works• Perceived Value. “One thing people really need is to be seen as valuable, because as soon as someone is not valuable in your eyes, it doesn’t matter how physically attractive they are, it’s game over.”Psychological research has shown that both men and women factor value judgments—think ambition and income—into their romantic decisions. Both sexes are more eager to date people they are told have higher earning potential. But it’s not just about education or money. A person’s overall value comes from many aspects of their life. Hussey explains that every guy is “looking for certain things that show him that he’s going to be able to be around this woman for a long time.” In the lab, personable characteristics like being fun, responsive, dependable or friendly also strongly influence whether someone will want to go on another date.• Perceived Challenge. “Perceived Challenge is just showing someone that they have to earn your value,” explains Hussey. Decades of scientific research have found that we tend to appraise things as worth more if we have to work harder to get them, whether it be products or people. Simply raising the price of a product, for example, makes us believe it’s higher quality. The same idea works when it comes to people—if we think someone is a challenge, we think more highly of them, and we are more willing to invest in the relationship.Most women have encountered the advice to be cool and aloof at first, to give the impression of being unattainable. “When someone says ‘play hard to get,’ ” Hussey explains, “they’re appealing to that Perceived Challenge part of the formula.” But Hussey isn’t a fan of this age-old dating rule. It’s sort of on the right track, but his issue with playing hard to get is that “it’s not effective in the long run.”MORE: Are You Dating a Commitment-Phobe?Of course, the opposite doesn’t work either. No one wants to feel like they’re rescuing someone from a lifetime of loneliness and depression. “He wants to feel like he’s convincing you that your happy, amazing life now would be even happier and more amazing if you were with him.”So how do you show someone that you are valuable and challenging without playing games? “Decide the standard that you want for the people around you, and the people that you date, and the people that you fall in love with,” says Hussey, “and then live that standard yourself. Standards make you challenging without having to pretend that you don’t like someone.”Psychologists have found that the root of preferring high-value, challenging partners is a selfish one—that who we date is a reflection of who we think we are. We are more attracted to people who validate and boost our own self-image.• Connection. As important as Visual Chemistry, Perceived Value and Perceived Challenge are, it’s this final element that matters most. “If you only have the first three, what you really have is someone you really admire and think is hot,” explains Hussey. “You can really only love someone when you have all four.”MORE: 5 Proven Tips for Meeting the Man of Your DreamsConnection is about shared interests and values—the feeling that you could tell someone everything. This aspect of the formula is where dating sites might be on the right track. Hussey and scientists agree that the major upside to online dating is that the algorithms automatically remove most of the people whom you’re truly unlikely to click with.The idea that “opposites attract” isn’t really true—we tend to feel more connected to people who have similar interests and values, and thus we tend to feel more attracted to similar people. Striking differences in values, in turn, tend to doom relationships. Dating algorithms focus heavily on similarities, and thus help narrow the field of people to those with the greatest chance at being matches. “Certain dating sites may be able to collect data that allow them to banish from the dating pool people who are likely to be poor relationship partners in general,” says Karney and his colleagues.But it’s not necessarily the quality of matches that makes online dating work for many—it’s the quantity. The importance of quantity when it comes to dating can’t go understated. “[Online dating] offers unprecedented (and remarkably convenient) levels of access to potential partners, which is especially helpful for singles who might otherwise lack such access,” says Karney and his colleagues.As Hussey explains it, think about the last 100 potential partners you’ve met—not the ones you ended up dating, but every man or woman whom you interacted with that, at least based on their gender and sexual orientation, might have been a potential date. Odds are, only 10 of them met your criteria when it comes to looks and interests, such that you were attracted to them on some level. Of those, maybe one or two were people you truly connected with and had a chance at a real relationship with. Now, how many potential partners do you meet in an average week? For most of us, the answer is zero, maybe one. At that rate, it not only could take years to find someone—it mathematically should.MORE: Meditate to Get a Date“If right now you are going on five dates a week because you are on a dating site, but otherwise you wouldn’t be going on any dates a week, then great,” says Hussey. Simply increasing the number of people you meet dramatically increases your odds of finding that someone you want to spend the rest of your life with. Online dating does that, but it’s not the only method. The more you interact with the people around you, whether it be striking up a conversation with the guy behind you in line at the supermarket or joining a running club, the more likely you are to meet that special person.As far as the science goes, algorithms and calculations might be able to weed out a good number of bad matches, but they aren’t going to scientifically find you Mr. Right. The reason online dating works for many is because it brings together a large number of people who are looking for a relationship and connects them with others who have enough similarities to have a shot in hell at being compatible. There’s no evidence, though, that it does this any better than we do in our offline lives, like when we meet people through friends or engage in social activities. Science can evaluate what makes for a great relationship, but it’s not as good at predicting the future based on personality tests.A little disheartened by what I’d learned about the science of matchmaking, I asked Hussey to speculate a little. Sure, maybe our current methods don’t have the predictive power we might want, but what about eventually, in some sci-fi future? Does he think we will ever be able to use scientific tools to truly predict relationship happiness?“Yeah, I do,” he said. “We probably could.” But, he added, “part of life is discovering.” Meaning, trial and error, headache and heartbreak—they’re what makes falling in love so magical in the first place. Bypassing all of the frustration would take some of the fun and excitement out of dating. So even though there is some future where we can calculate love with mathematical certainty, Hussey wants no part of it: “It’s not a world I ever want to live in.”MORE: How to Be Lucky in Love