A matchmaker will tell you that in order to hit it off with a guy, you need to have common interests, shared values and similar backgrounds. But the heat and spice come from chemistry – that enigmatic, intangible ingredient that makes two people click. And though there’s no way to predict exactly who you’ll fall for, understanding these laws of attraction can help you find – and hold onto – your soulmate.

You’re Equally Attractive

Given the chance, you may decline to hook up with that Robert Pattinson lookalike. “Just because someone is gorgeous doesn’t mean you’ll want to pursue them,” says biological anthropologist Dr Helen Fisher, author of Why Him? Why Her?

“People tend to be attracted to others on their same physical level.” An average-looking person will often seek an average-looking mate, whereas “classically” beautiful people usually pair up. (Kinda explains Brangelina perfectly, doesn’t it?) “People are drawn to those who offer the best success rate – someone who won’t reject them,” Fisher says.

You Have Soundalike Names

The fact that many couples have similar monikers (say, Jen and John) may seem coincidental, but it’s actually a subconscious choice. “We often pair up with others who have identical initials or similar names because we’re conditioned to like what feels familiar,” says psychologist Kevin Hogan, author of Irresistible Attraction: Secrets of Personal Magnetism. If your names aren’t similar, coining complementary pet names can achieve the same bonding effect.

You Share the Same Quirky Habit

You love foreign films; he watches Die Hard flicks. Doesn’t matter. Compatibility is based on common offbeat interests – a shared penchant for recording your dreams, a mutual love of anchovies.

“People admire others who mirror their idiosyncrasies,” Hogan says. “When someone understands your quirks, it creates an instant bond.” Discover commonalities by asking him, “What was your oddest childhood habit?” or “If you could have only three items, what would they be?”

You Want to be More Like Him

We’re innately drawn to people who possess a character trait that we lack. “People generally choose partners who keep them balanced,” says Kammila Naidoo, a sociology professor at the University of Pretoria.

“South African women are commonly drawn to men who display quite different characteristics and qualities from themselves. Complementary differences can make a woman feel fulfilled, or ignite a hidden or latent side of her own personality. So if you’re dating someone who is confident and self-assured, and you’re not, you could reap some positive spin-offs in time.”

Got a crush on your polar opposite? Go with it. His positive traits will likely rub off on you, making you more well-rounded.