The Neuroscience of Love
What is love? I am sure most of us have experienced some type of love in our lives and can describe how it makes us feel. But what exactly are the mechanisms of love and what makes us behave the way we do? As it is Valentine’s, let’s delve into the neuroscience of love.
Love can come in many forms, whether it’s the love you feel for a friend or a family member, or the love you feel for a partner or someone you are attracted to. According to Dr. Helen Fisher, love can be divided into three categories, lust, romantic love, and attachment – each characterized by its own set of hormones and behaviors (Fisher, Aron & Brown, 2005).
I’m in Lust with You
Lust is the rush of intense desire and cravings you experience when you first meet someone you think is really attractive. It is an innate set of emotions that drives mating behaviors and is controlled by the sex hormones estrogen and testosterone. It motivates individuals to seek sexual gratification.
During this infatuation stage, there is also a rise in cortisol, a stress hormone that contributes to that excited, nervous, “butterflies in my stomach” feeling (Seshadri, 2016). Researchers have found that there is reduced brain activity in the frontal cortex, a brain region associated with judgment and decision-making (Zeki, 2007). That’s why in the beginning stages of love you may act irrationally.
Your Love is My Drug
Romantic love is closely related to lust, and both can certainly co-occur, but romantic love is what drives coupling when the initial lust dies down. To determine the neural mechanism of romantic love, Fischer and her team (2005) put loved-up individuals into an fMRI machine. They found activation occurred in the right ventral tegmental area and the right caudate nucleus, dopamine-rich areas in the brain associated with reward and motivation.
The reward pathway in the brain drives behaviors towards pleasurable stimuli, when we spend time with a romantic interest the primary pleasure neurotransmitter dopamine floods the reward circuit – eliciting feelings of euphoria and enjoyment. As a result, we end up associating that stimuli or person with positive feelings, making us want to spend more time with that person as they make us feel good (Schultz, 2015).
Interestingly, many drugs hijack this pleasure pathway, the behaviors and actions seen in the early stage of romantic love are not too dissimilar to those of addicts. A person newly in love usually experiences intense emotional responses such as euphoria, highly focused attention on their beloved, obsessive thoughts about the person, emotional dependency, and craving for emotional union with that person. Your beloved literally becomes your drug (Zou, Song, Zhang & Zhang, 2016).
If you can’t be with your loved one or if the relationship ends, heartbreak mirrors the common signs of drug withdrawal, such as lethargy, anxiety, insomnia, or hypersomnia, loss of appetite or binge eating, irritability, and chronic loneliness. Just like a person suffering from addiction would relapse and seek their drug of choice, a rejected lover would try to win their beloved back, much in an attempt to get one last fix (Zou et al., 2016).
I’m in it For the Long Run
Over time, the physiological “crazy in love” feelings gradually subside, and you enter the stage of attachment which is associated with commitment, calm, safety, and balance (Fisher et al., 2005). This type of love is not exclusive to romantic partners, it’s also the love we feel for family and friends. Attachment helps us to maintain close social bonds and keeps relationships going for the long term.
This type of love is driven by the hormones oxytocin and vasopressin, which are produced in the brain by the hypothalamus. Oxytocin is known as the “cuddle hormone”, just as the nickname suggests, oxytocin is released when you receive a hug. It also drives childbirth and mother-child bonding (De Boer, Van Buel & Ter Horst, 2012). Vasopressin is associated with the mate-guarding aspect of monogamy and plays a bigger role in attachment in males who benefit less from oxytocin (De Boer et al., 2012; Carter & Perkeybile, 2018).
One study demonstrated the pair-bonding effects of oxytocin and vasopressin in attachment by investigating the reproductive habits of two closely related voles. The prairie vole forms pair bonds for life while the montane vole is more promiscuous. It was found when oxytocin and vasopressin receptors in the brain of prairie voles were blocked, they behaved promiscuously; whereas the montane voles became monogamous when levels of these hormones were increased (De Boer et al., 2012).
Now, if you’re a budding scientist like myself, you might have thought after reading the above-mentioned study “oxytocin and vasopressin could work as a love potion”. There are some questionable “love potions” available on the internet, however, it’s not that straightforward. These hormones work on several receptors in the body, which can lead to several unwanted side effects such as cardiovascular dysfunction (ironically) (Japundžić-Žigon, 2013).
The Magic of Love
Overall, love is not a single emotion but a set of emotions and behaviors that drive relationship formation. When in love you feel sexual excitement and euphoria, you literally can’t stop thinking about that person – you crave their love and affection. If it works out, over time, this initial giddiness is replaced with the warm embrace of calm and commitment.
Despite science telling us that love is just a complex interplay of hormones, neurotransmitters, and neuropeptides, for me, this doesn’t take away from the magic of love.
References
Carter, C. S., & Perkeybile, A. M. (2018). The Monogamy Paradox: What Do Love and Sex Have to Do With It? Frontiers in ecology and evolution, 6, 202. Available from: https://www.frontiersin.org/articles/10.3389/fevo.2018.00202/full
De Boer, A., Van Buel, E. M., & Ter Horst, G. J. (2012). Love is More than Just a Kiss: a Neurobiological Perspective on Love and Affection. Neuroscience, 201, 114-124. Available from: https://www.academia.edu/17619302/Love_is_more_than_just_a_kiss_a_neurobiological_perspective_on_love_and_affection
Fisher, H., Aron, A., & Brown, L. L. (2005). Romantic Love: An fMRI Study of a Neural Mechanism for Mate Choice. Journal of Comparative Neurology, 493(1), 58-62. Available from: http://www.helenfisher.com/downloads/articles/13JourCompNeur.pdf
Japundžić-Žigon N. (2013). Vasopressin and Oxytocin in Control of The Cardiovascular System. Current Neuropharmacology, 11(2), 218–230. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3637675/
Schultz, W. (2015). Neuronal Reward and Decision Signals: From Theories to Data. Physiological Reviews, 95(3), 853-951. Available from: https://journals.physiology.org/doi/full/10.1152/physrev.00023.2014
Seshadri K. G. (2016). The Neuroendocrinology of Love. Indian Journal of Endocrinology and Metabolism, 20(4), 558–563. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4911849/
Zeki, S. (2007). The Neurobiology of Love. FEBS Letters, 581(14), 2575-2579. Available from: https://www.sciencedirect.com/science/article/pii/S0014579307004875
Zou, Z., Song, H., Zhang, Y., & Zhang, X. (2016). Romantic Love vs. Drug Addiction May Inspire a New Treatment for Addiction. Frontiers in Psychology, 7, 1436. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5031705/
