How can body language be used to detect attraction?
I don't mean to teach you secret exploits you can take advantage of in your romantic endeavors, but hopefully you'll still pick up some tips on figuring out if a person is interested in you at all (the rest is up to you!).
I've mentioned eyelid-raising as a nonverbal behavior of excitement, but there are many more ways to tell if a person is interested in you, and we'll start by looking at what men do.
It all comes down to the manhood.
If a man stands tall, spreads his chest, and put his hands somewhere on the belt line (also known as the "Superman pose"), he is trying to show off his masculinity. Displays like this are designed to dominate attention, even if you're alone. This particular pose also opens up the pores in the armpit where pheromones, chemicals that trigger social responses, are released--a biological sign of sexual attraction. Making the front open for viewing also allows the man to proudly display his groin, which works like how a male peacock displays his tail feathers to a female.
Another thing you can look for is feet placement. When you are having a conversation with anyone, feet facing directly at you usually means that the person is truly interested in your conversation. If the person would rather be someplace else, the body often reflects that by orienting itself toward the nearest exit. A man leaning into your personal space is also a pretty good indication of interest.
These are very basic signs of attraction, but then again men aren't notorious for being difficult to read.
Women: the mystical maze of wonder.
So how can you tell if a woman is interested?
One of the most common signs of romantic interest is the hair-flick. Women flick their hair to the side, no matter how short it may be, to bring attention to their face. It's a pretty good sign if a woman wants you to see more of her. The physical act of flicking the hair also frees up space near the armpit for pheromones to travel through, much like men (if you haven't noticed yet, many of our nonverbal behaviors are directly adapted from biological mechanisms for survival).
The "facial pedestal" works in a similar way. This is when a woman joins her hands together and rests her face on them. This does not mean she's bored--she wants to bring her face to your attention so you can give her a compliment.
There are other ways a woman can attract attention as well. We have several spots on our bodies that are vulnerable, namely the neck, throat, and wrist. When we feel comfortable around a person, we tend to display behaviors that show those parts. A neck tilt is a very positive sign of attraction, as are actions that draw attention to a woman's wrist. If you've seen movies where the female romantic interest is a smoker, she often holds her cigarette by the side of her face, eye-level, and wrist facing the other character.
These are all simple and obvious attraction signs that go criminally overlooked. A strong indication of attraction is any behavior that is designed to bring something to your attention.
Bottom line: if they are trying to get you interested, then they are interested.
Cox, T. (2011). 18 Body Language Clues That Say He's Interested--Definitely. Retrieved from http://www.ivillage.com/18-body-language-clues-say-hes-interested-definitely/4-a-283709?p=1.
Hesketh, D. Body Language of Sexual Attraction Between Male and Female. Retrieved from http://www.cheshiretherapy.com/index.php/Latest/body-language/All-Pages.html.
Michael, M. (20110). Body Language: Signs of Attraction. Retrieved from http://sapientology.com/body-language/signs-of-attraction/.
Navarro, J. (2008). What Every BODY Is Saying: An Ex-FBI Agent's Guide to Speed-Reading People. New York: Harper Collins.
Pheromone. (n.d.). In Merriam-Webster's online dictionary. Retrieved from http://www.merriam-webster.com/dictionary/pheromone.