Yea for serotonin and oxytocin!

I did a little research to find out what chemicals were involved in attraction with the opposite sex, everything from hugging all the way up to the act of sex. Here are some of the chemicals that play a part: norepinephrine, serotonin, oxytocin, vasopressin, nitric oxide, and the hormone prolactin

A lot of these play major parts in other functions as well such as sleep and maintenance of hydration through out the body. Some of the chemicals are responsible for feelings of bonding with others and much of the feelings associated with love. I find that interesting that much of how we respond to others is based off of a chemical reaction with in our bodies. Granted our actions effect how the chemicals are released but still.