As a romance writer, it's impossible to ignore the symptoms of falling in love, for the simple reason that they need to be described from both my hero's and my heroine's points of view. It's important therefore to know what these symptoms are and to have a wide variety of ways in which to bring them to life so the reader isn't always faced with yet another 'racing heart'. And yet, scientifically, a racing heart (when you're not under physical stress or experiencing some other powerful emotion, like fear - but in the presence of the opposite sex), is one of the prime indicators that you want to...well, there's really no delicate way of putting this... We're not talking about long term commitment yet, but the primal instinct to populate the planet with someone that your body - miracle machine that it is - believes will make a fine match for your genes, has kicked into action. That's right! Your brain will quickly determine the suitability of the other person (potential mate) by deciding whether or not they contain attributes that you would like to be passed on to your children. Nobody has necessarily asked anyone out on a date yet, but your mind is already leaping ahead and contemplating the result of a long term commitment, albeit on a subconscious level.
But there's more than genes at play when determining who your eventual life partner will be. In fact, according to Helen Fisher of Rutgers University in New Jersey, there are three stages to falling in love.
The first happens to be lust, driven by the sex hormones testosterone and oestrogen. These are the hormones that will make your subconscious forget about looking for that ideal gene match in favor of just 'looking for anything.'
After lust comes attraction. This is that 'new love' feeling complete with butterflies in your stomach, the inability to eat and sleep and that sense of panic that comes over you when the guy you like doesn't call. This is because of a group of neuro-transmitters called 'monoamines.' They include dopamine, (which is also activated by cocaine and nicotine) norepinephrine, otherwise known as adrenalin (this is what causes that racing heart), and serotonin, a chemical capable of making us go temporarily insane. Remember that crazy ex-boyfriend/girlfriend? Now you have an explanation =) Since it isn't practical for the attraction stage to last forever, it gradually evolves into the attachment stage, provided that there's enough compatibility for the relationship to last. During this stage, two hormones intended to bind couples together, are produced. They are oxytocin and vasopressin.
Now, this is where it gets really interesting. You see, monogamy/faithfulness toward your partner, isn't just encouraged because it's believed to be the correct behavior. It's actually enforced through sex. Yes. So Cool! That's because oxytocin, a hormone released by the hypothalamus
gland during child birth which helps the breasts express milk and forms a strong bond between mother and child, is also
released by both men and women during orgasm. Fascinating stuff, right? So, to clarify, oxytocin is thought to promote bonding between adults who are intimate. In other words, the more sex a
couple has, the greater their attachment becomes.
Vasopressin is also important to
long-term commitment. In an experiment with prairie voles who also form long term attachment by mating more than necessary for the sake of reproduction, the male voles in which vasopressin was suppressed, lost interest in their partners and allowed them to seek other suitors.
Below is a really fun diagram illustrating the entire process. Thanks for sticking around and feel free to comment =)