The Science Behind Falling in Love

Recently, I have had the wonderful experience of watching a close friend fall in love. She smiles when she talks about her mate, or talks about him at random times—evidence that she is thinking about him a great deal. I could not be more delighted for her. Within a few days, it started to happen to another friend of mine, too, with the same sort of reaction—although in her case, it was accompanied by a loss of appetite. And then, a few more people reported via Facebook that they had fallen in love with someone.

I was initially surprised by the fact that so many people are falling in love around me, despite it being winter. Some scholars have speculated that the best time to find lasting love is the fall, with summer being the best time to find short-term relationships. Winter, they argue, is a difficult time to find someone because many of us reduce our activities, as well as wear less revealing clothing. Many people also have decreased mood, due to less (and weaker) sunlight. (I should mention that in the case of my love-stricken friends, all of them live in a place where there are currently freezing temperatures.)

Being around people who are falling in love is fun (partly because under normal conditions, these people might not act so silly), but it can also be depressing, especially if one is in an unsatisfying relationship. Social comparison can be a nasty part of human nature. (I will comment more about this in a subsequent post.)

Although people experience love differently, the chemistry behind the initial rush of attraction shows us that there are biological explanations to feeling giddy, for example, during those blissful early weeks.

To start with, dopamine, which is created in the brain and adrenal glands, enhances the release of testosterone. Dopamine affects various organs, including the genitals and the sweat glands, as well as the senses. Have you ever noticed that when you are in the early stages of lust or love, you sweat more? Or that the sky seems bluer? Dopamine, in this context of arousal, is partly responsible. As a consequence of dopamine being released, mood and emotions are also influenced, leading to feelings of excitement and happiness. Meanwhile, testosterone increases sexual desire, but also increases aggressive behaviour and may push someone to pursue the one who is fueling this intense response.

After this step, the neurotransmitters norepinephrine and PEA (phenylethylamine) lead to focused attention. Individuals start to "zero-in" on the person they desire, and at the same time, often have a feeling of euphoria. Norepinephrine is a stimulant, so it also causes individuals to feel alert, potentially unable to sleep, and enables them to notice and remember even the smallest of details about their partners. PEA is responsible for the feelings of giddiness, and may cause a loss of appetite. If the relationship doesn’t last, PEA levels fall and are partly responsible for the feelings of depression that can be experienced.

A feedback loop begins to form, and the brain's reward system becomes involved. This reward system is influenced by the central nervous system and the contents of the bloodstream, such as the level of various neurotransmitters. The reward system sends chemical messages, via neurotransmitters, to various parts of the body, including the stomach, skin, genitals and other organs, which causes them to send messages back to the brain. To phrase it simplistically, if stimulation of the genitals feels good, for example, then the reward system receives this information and causes one to seek more of what was pleasurable. Interestingly, anticipation alone can cause a biological response and stimulate the reward system.

During the initial stages of love or lust, this reward system is stimulated through very simple means; a lover’s touch, seeing their photograph, or even just thinking about this person can increase elevated mood and focused attention. Helen Fisher and colleagues (2005) found that when the brains of those who state they are passionately in love are scanned by an fMRI, the reward system is activated.

Where the relationship goes from here becomes increasingly complicated. Some might fear the possibility of rejection, which overrides their enjoyment of falling in love. Others may be scared about committing to the relationship, or be overly needy and clingy—and, as a result, drive their lover away. Some may dive in, secure in their hopes that this might be the relationship that lasts. These patterns are thought to start in the early stages of development, and reflect the parent-child relationship. This early relationship, although not romantic, teaches us about how relationships work, what we can expect of others, and whether relationships—of any kind—are worthwhile. (There are various ways to assess one’s attachment style; if you’re curious, there are many quizzes available online.)

Although there are many benefits of being single, there is no denying that falling in love is an intense time, and one that most of us find exhilarating. The next time someone you know starts to comment on the smell of the outdoors being more refreshing than usual, or you notice they grin when staring at a photograph of someone they are dating, enjoy the show—and know that they are possibly falling in love.