Eli Finkel was still an undergrad when he realized "somebody could spend his life asking questions about relationships, trying to find the answers to those questions and then teaching interested young minds about the research."

But when, as a newly minted psychology professor teaching a course on romantic relationships, he faced questions from a discerning student about how couples paired off, he was stumped.

"I kept being like, 'I don't know and the field doesn't really know,' " he recalls. Research on attraction had been done in the '50s and '60s, but was largely abandoned after that. It has come back into academic fashion in recent years, however, led in part by Finkel's work with that former student, Paul Eastwick, now an assistant professor at Texas A&M.

Speed-dating events became their petri dish of choice — "it was this extraordinarily rich social context for studying initial attraction," Finkel explains.

In a 2005 study, they looked at whether the characteristics singles say they want in a partner match what they actually pursue.

On paper, women reported a greater desire for earning potential and status; men were more interested in physical attractiveness.

In person at speed-dating events, that discrepancy went away — "women want really good-looking men every bit as much as men want really good-looking women," Finkel says. And financial prospects were no less important to men than women.

The take-away, as Finkel sees it: "We tend not to have the insight that we think we do into our romantic preferences."

"Don't read a profile of somebody on Match.com and assume, 'Oh, well, that person doesn't match my shopping list of characteristics I need in a partner so there's no way I should go on a date with her,' " he cautions. "We can't evaluate people as abstractions. ... Life isn't lived on paper. It's lived in flesh-and-blood encounters, and there's magic that can happen in those encounters."

Another of Finkel and Eastwick's studies found that when it comes to platonic relationships, if a person tends to like everyone, that good will is more likely to be reciprocated.

But in romantic relationships, that wasn't the case. If a single guy digs ALL the women in the room, Finkel explains, "the women don't like him back."

The turn-on, he continues, comes when a person feels "uniquely desired." "When he or she has set sights on me, that seems to be something of an aphrodisiac," says the 34-year-old psychologist, who was set up with his wife by his grandmother.

Finkel and Eastwick's most recent study questions why women are so often found to be more selective in choosing partners than men.

In almost all speed-dating events, women sit in stationary positions and men rotate to talk with each of them. When Finkel and Eastwick set up a dating event like that, the standard result bore out — women were more selective.

But when they reversed the roles and had women rotate, that was no longer the case. Suddenly, the men became more selective and the women less so.

Finkel postulates that the very act of making an approach changes the dynamic between two people — the one who walked up is more likely to feel attracted to the person sitting across from him or her.

"If you're somebody who's reliably felt, 'I just can't find anybody interesting,' take a bit more initiative," he says. "If you see someone who's potentially interesting, stand up and walk over there. Who knows — it could at least inspire you a little bit."