7 things people need to fall in love

Romantic love might seem like a mystery, but it's not really, at least most of the time - researchers have done their best to figure out what exactly it is that draws people together.

Psychologists have identified ten factors that can generally explain why we fall in love with someone, according to Elizabeth Phillips, a Ph.D. student in applied experimental and human factors psychology at the University of Central Florida.

Phillips gave a talk at the Nerd Night Global Festival about some of the ideas put forth in David Levy's book "Love+Sex with Robots." Levy has written about exactly what makes us fall in love, and his list of the ten factors involved does a great deal to explain just how the falling-in-love process works.

Here's what it takes:

1. Relationship readiness. Someone has to be psychologically at a point where they would choose to enter a relationship. A great example is right after a person has exited another relationship - the rebound effect.

2. Alone time. This factor, exclusiveness, is essential for falling in love. Spending time alone with someone makes it easy to get close to them.

3. Desirable characteristics. This covers a lot of what we find attractive in the first place: appearance and personality. Phillips explains that people rate the importance of these factors differently: some people might love a great personality and others might value appearance more, but we all have aspects of personality or physical attractiveness that we find important.

4. Social acceptability. Someone has to fit into whatever category of people we think it's acceptable for us to fall in love with. Phillips calls this "social influences," and says that explains the cultural norms and limiting factors about who we can fall in love with - like whether or not someone is within an acceptable age range for us. These norms have changed significantly over time.

5. Need fulfillment. Some of us need someone we can be close and intimate with, others are after the boost in social status that might come with a certain partner. Whether you need a cuddle or a trophy, the people that we fall in love with generally meet some sort of need in our lives.

6. "Arousal" situation. No we're not talking about sex here (most of the time), but being in an exciting, stressful, or dangerous situation that gets your adrenaline going with another person is a bonding experience that's associated with falling in love.

7. X-factor. Someone has to have that special something that turns us on. For some of us, this might be shapely legs or eyes you get lost in, for others, a killer sense of humor. We've all got specific characteristics that we find attractive and we tend to fall in love with people who have those characteristics.