- adrenaline - which causes the heart to race, the body to sweat and the mouth to go dry
- dopamine - which stimulates 'desire and reward' by triggering a rush of pleasure, not unlike a cocaine high
- and serotonin - which keeps the brain focused on one thing: that other person.
- oxytocin - released by both men and women during orgasm. The more orgasms a couple experiences together, the more oxytocin is released and thereby the more connected they feel to each other. (By the way...oxytocin is also the same hormone released between a mother and child during childbirth and it's the same hormone that stimulates a mother's breast to release milk at the mere sight or sound of her child.)
- and vasopressin - a hormone released during sex. The more sex a couple engages in, the more vasopressin is released in the brain, which deepens their connection and in some cases triggers males to become aggressive toward other males who show interest in their females.
Is there a time frame on each of these stages of love? Not specifically. Some couples go through them quickly, others take longer. A lot depends on how each person was raised, their previous experiences and their attitude toward relationships.
So what happens when two people are placed in a life or death situation? This happens in romance novels quite a bit. Someone's out to get the hero or heroine. They're on the run. Danger lurks around every corner. It is believable that two people can fall in love during extreme situations especially when their time together spans only a few days, and more importantly...is it believable that they can sustain that love once once the danger has passed?
Well, let's look at what happens to the body when you're in danger. When the body is under extreme duress, the autonomic nervous system signals the adrenal gland that it's time to release adrenaline. Adrenaline, remember, is an important hormone during the attraction phase of falling in love. When you're attracted to someone, your heart races, your body sweats, and your mouth may feel dry. When your body is threatened, these same symptoms result, often triggering the fight or flight response. And when that threat happens to both you and the person you're insanely attracted to, those fight or flight responses are magnified. A lot.