Single ladies, you might be sabotaging your romantic chances if you hang out with a posse of guy friends, according to a Texas Christian University study. The researchers surveyed men, and found that women were rated equally attractive whether they were alone or with other women. But the attractiveness dropped dramatically when a woman was surrounded by a group of men.

That's because there's a good chance she's already spoken for, believes Sarah Hill, professor of psychology and coauthor of the study, which deters most suitors.

Bottom line: Plan a girls night out; you might find Mr. Right.

If you want to know more about the guy you're dating, his family tree is a good place to start -- or more specifically, his birth order or the order he was born into a family. "While other factors, such as age, race, and gender, all play a role in shaping personality, research indicates that the number one factor influencing personality is birth order," explains William Cane, author of The Birth Order Book of Love, who has analyzed the birth order of 6,000 celebrities, historical figures and couples.

Birth order personality
Firstborn
Because firstborns are usually given more responsibility from young to look after their siblings, they typically grow up to be dominant, super-responsible, organized and competitive.

Middle child
The middle child is a people-pleaser. He or she is diplomatic, and it's difficult to get them to take a stand. The middleborn also tends to be a little manipulative.

Lastborn
Lastborns are friendly, creative individuals who love challenging the status quo. They're more adventurous than their siblings and are the risk-taker in the family, although they also tend to be needy at times.

Only child
An only child is used to being in the spotlight within the family, so he or she tends to crave attention. Being an only child also means that he or she is unlikely to know very much about the opposite sex.

Twins
Twins have a strong bond and therefore always think of the other before making a decision. Their thoughtful nature makes them considerate romantic partners.

If you're fishing for a potential date, here's a piece of advice for you: Don't do it when you're drunk.

The "beer goggles" phenomenon is real, say scientists from the University of Bristol in the UK, who conducted a research involving 84 heterosexual college students. The students were given either an alcoholic lime-flavored drink (enough to make some students tipsy) or a non-alcoholic version. After 15 minutes, they were shown pictures of people their own age, from both sexes.

The students who had consumed alcohol rated the faces as being more attractive than those who did not. In addition to increased perceptions of attractiveness, previous studies have also shown that alcohol lowers inhibitions, and drinkers are more likely to engage in risky sexual acts.

With more and more people finding love online, this factoid can prove useful: Namely, your date's profile on online networking sites (such as Facebook) can reveal whether he's actually a narcissist.

Researchers from the University of Georgia gave personality questionnaires to nearly 130 Facebook users and analyzed the content of their online profiles.

What they found is that the number of Facebook friends and wall posts (messages left by the owner of the profile or friends) that a person has correlates with narcissism. Laura Buffardi, a doctoral student in psychology, said this is consistent with how narcissists behave in the real world, with numerous yet shallow relationships.

A self-obsessed Facebook user will boast thousands of friends and update their "status" non-stop. "Sometimes they'll have a famous (Ralph Waldo) Emerson quote, but they'll include quotes from themselves or something flattering someone else said about them," Buffardi said.

And guess what, narcissists are also more likely to choose glamorous, self-promoting pictures for their main profile photos, while others are more likely to use snapshots. So if you see him posting photoshopped, look-at-me pics of himself, he probably has a narcissistic streak.

How can you tell whether a guy really likes you or if he's just looking for a casual hook-up? According to anthropologist David Givens, Ph.D., who specializes in nonverbal communication, when a man is serious about the relationship, he demonstrates loving acts that show he cares. So, you know you're more than just a fling when he:

• Holds your hand
• Grooms your clothing, or plays with your hair 
• Doesn't lose interest after the third date if sex hasn't occurred 
• Calls you the day after making love 
• Doesn't let his eyes wander when he's with you 
• Attends to your needs (but not excessively so)
• Touches your arm, shoulder, or back -- but not at every opportunity 
• Doesn't make a pass on the first date

What your date orders at Starbucks says tons about his personality, according to Dr. Alan Hirsch, Director of the Smell & Taste Treatment and Research Foundation and author of What's Your Food Sign?

It may sound a tad far-fetched, but Dr. Hirsch has some science to back up the statement: His survey of 18,631 men and women revealed a strong correlation between the participants' drink preferences and their personalities.

Here's what his coffee order says about him:

Black coffee: He's aggressive, ambitious and independent

Café au lait: He's traditional and laid-back

Chai tea latte: He's shy and stubborn

Hot chocolate/ Mocha-flavored coffee: He's a dreamy romantic

Iced mocha: He's spontaneous and seductive

Iced tea with lemon: He's sexually shy and inhibited

Whatever it is, apparently it's not money.

In fact, a new study featured in Psychology Today shows that the higher the woman's IQ, the less swayed she is by her date's fat wallet.

The research by University of Michigan graduate student Christine Stanik, which focused on mate selection and romantic relationships, also found that women with higher IQs don't mind marrying later, nor being the breadwinner.

So what does this indicate? Stanik believes smarter women tend to be financially-independant. They're less likely to conform to traditional gender roles, and therefore place a higher emphasis on other appealing qualities when it comes to choosing their life partner, such as the ability to be a supportive spouse and nuturing parent.