The biological basis of love, aimed at explaining what really happens to your body when you are experiencing love, has been continuously studied by other sciences such as evolutionary psychology, evolutionary biology, anthropology, and neuroscience.
Researchers and scientists have long been fascinated by this intense feeling and emotion felt by people, yet it is still not completely understood.
What they do know is that certain chemicals in the body, hormones and neurotransmitters, are involved in producing the euphoric feeling often associated with love and why people fall in love. These chemicals, when triggered, are responsible for passionate love and long-term attachment. Neuroscientists have used scanning technology to map out the chemical changes that occur in the brain during courtship, the initial stage when people start to find themselves falling in love. Semir Zeki and Andreas Bartels, professors of neuro-aesthetics at University College, London explain that when you look at someone you are passionate about, some areas of the brain become active. These areas in the brain were associated with instinct and feelings of euphoria.
Furthermore, researchers have associated that initial giddiness of falling in love including racing heart, flushed skin, and sweaty palms with the brain chemicals being released. These are dopamine, norepinephrine, and phenylethylamine.
Studies have shown that dopamine production is increased in those who are in love— it serves as the key to experiences of pleasure and pain and has also been linked to desire, attraction, and euphoria. A surge of dopamine can cause acute feelings that make it hard for people to give up love. There may be a good cause to describe falling in love as “addictive” since taking opioid drugs such as cocaine to have a similar effect on dopamine as love.
Norepinephrine, similar to adrenaline, produces the racing heart and excitement associated with seeing the person you are attracted to. According to Dr Fisher, norepinephrine together with dopamine produces a sense of elation, intense energy, sleeplessness, craving, loss of appetite, and focused attention.
Phenylethylamine, naturally occurring in the brain and in some foods like chocolate, is a stimulant that further causes the release of norepinephrine and dopamine. Other hormones like serotonin also play a role. However, people who are in love were known to have lower levels of said hormone. This fall in serotonin levels has also been associated with people who have obsessive-compulsive disorder, which may explain why people in love tend to focus intently on the object of their affection and much less on anything else outside the relationship.