The Neuroscience of Love

Falling in love seems to be an essential part of human nature. It’s universal—we all know what love is even if we have a hard time defining it or detailing its complexities. And love transcends cultural and societal differences: in a historical study of 166 societies, anthropologist Helen Fisher found evidence that feelings of love existed in 147 of them. Thus, it appears we are not taught that love is important to us, but rather may be born knowing it.

But anyone who has ever been in love knows that love is complicated. Being in love can calm you down, but it can also make you anxious. In our attempts to understand how the human brain works, neuroscientists have studied for decades what the complex mix of emotions we call love does to our brain. Can love cause us to lose focus? Is being in love addicting? And can science weigh in on the question of whether or not love can last?

Let’s find out today.

Our Brains See Love as a Reward

In a 2005 study, researchers compared functional MRI images of the brains of 2,500 college students while looking at someone they love relative to looking at an acquaintance. Scientists were thus able to map which regions of the brain are active when a person is experiencing feelings of love. They saw the most activity in two regions associated with seeking and detecting rewards, namely the caudate nucleus and the ventral tegmental area. These regions are also responsible for an increased production of dopamine, the feel-good neurotransmitter. Neurotransmitters are chemicals that pass information from one neuron to the next. In the case of dopamine, that information is a signal to the brain that the person is feeling happy and finds the current activity rewarding.

Love Can Be Addicting

The increase in dopamine levels can act as a high or even inspire a state of euphoria when around the object of affection. In an effort to continue that lover’s high, you may find yourself wanting to be around the other person all of the time.

The part of our brain that processes attraction, often a precursor to love, is known as the opioid center and is, as you may have guessed, the same region responsible for our response to certain addictive substances including opioids like morphine. For example, in one, albeit smaller, study, a group of 30 men were given either small doses of morphine or a dose of an opioid suppressor. Those given the opioid rated attractive faces more highly and spent more time looking at them, suggesting that our brains can be primed to find others attractive by first stimulating the right region of the brain.

Also running high in love-addled brains are adrenaline, which can make your heart beat faster and your palms sweaty, and vasopressin, which triggers territorial feelings of loyalty and the need to protect. However, these same feelings of love are found to be linked to lower levels of serotonin, which may seem counter-intuitive. Serotonin is another neurotransmitter that, like dopamine, passes along the information that you are happy and feeling rewarded.

Serotonin is also linked to cognition, learning, and memory, and lower levels of serotonin are common in people with obsessive-compulsive disorders. So diminishing serotonin levels will increase your desire for your mate, and empirical evidence suggests that they may lead to reduced cognitive control. Reduced cognitive control is just another way of saying you can’t control where you focus your attention, similar to OCD.

Ever heard the expression “love is blind?” This obsession-like concentration on a lover or crush may be the reason your roommate can’t seem to see all the red flags that you find so obvious when it comes to her new beau.

Long Lasting Love Has Its Own Chemistry

The kind of love we have described so far is what neuroscientists have labeled passionate love or love in the early stages. But what about a longer lasting love? Does the chemical imprint left on our brain change as we age and relationships progress?

In the later stages of love, serotonin levels are found to increase, and dopamine surges are lowered to more normal levels. This combination means you feel less of the aching desire for your partner but instead feel a more secure, less anxious happiness. Oxytocin, known as the cuddle hormone, is also produced during close contact and strengthens bonds between partners. (Oxytocin is also produced during breastfeeding and skin-to-skin contact with newborns and is responsible for the strong bonds between mother and baby.)

One study attempted to compare directly the brain activity of couples in newly passionate love with those in loving, longer-term relationships (an average of 21 years of marriage). Again through functional MRI imaging, researchers determined that looking at a picture of their spouse triggered the same area of the brain in the long term lovers as those areas activated by feelings of passionate love, namely the ventral tegmental area. So even after 20 years of marriage, science says we can still find our relationship with our spouse to be rewarding and perhaps tap into a bit of that dopamine-induced lover’s high.