The Psychology (and Biology) of Love

“Love is an emergent property of an ancient cocktail of neuropeptides and neurotransmitters.”

​For hundreds of years, humans have struggled to define “love.” From Shakespearian tragedies to poetic declarations of desire, there are millions of ways to express the feelings of romantic love. While the above quote by Larry J. Young is not the most elegant description of love, it explains the biology behind love, and why we as humans are programmed to experience the joys and pains of romantic partnership.
 
According to a team of researchers at Rutgers University, romantic love can be divided into three main categories: lust, love, and attraction. Within each category are specific chemical reactions in the body, and these reactions influence what we socially define as love.  
 
Let’s start with lust. Frequently referred to as one of the “seven deadly sins” in Christianity, lust is the biological basis for reproduction and the evolution of the human species. Lust is driven by the evolutionary need for sexual reproduction and is one of the main reasons why so many species, humans included, spend a significant amount of energy and time pursuing a romantic interest. Hormones such as estrogen and testosterone begin to rise when we come across a person we find arousing. Think back on your first encounter with your significant other or a person you found attractive; perhaps your heart began to pound in your chest, your palms became clammy, and you stumbled over an awkward introduction. All these visceral responses to lust are a part of the normal, physiologic response to deeply engrained biological processes that have allowed humans as a species to flourish.
           
Closely related to lust is attraction. Attraction and lust are grouped into the same category in social and psychological definitions of love, but true attraction to another person originates in a different part of the brain with a unique set of neurotransmitter activity. Once we decide to pursue a romantic partner and label them as “attractive”, the brain begins to release dopamine, a neurotransmitter. Dopamine is associated with the reward system in the brain, and produces feelings of euphoria, excitement, and pleasure. As we spend more time with our romantic interest, the brain associates the attraction with an increase in dopamine. This biological process explains why we often feel as though we must spend significant amounts of time with a romantic partner, especially in the early stages of a new relationship. Increased levels of dopamine are also associated with a reduction in appetite and sleep: essentially, this means you can be so in love that you cannot eat or sleep…
 
As relationships progress out of the initial “honeymoon” phase, a new set of neurotransmitters and hormones take over. This final category is defined by the idea of attachment and is a predominant factor in the stability of long-term relationships. While lust and attraction are associated with romantic love, attachment can also span into other types of love and relationships with family members and friends. Attachment is highly linked to the release of oxytocin, another neurotransmitter. Oxytocin is sometimes referred to as the “cuddle hormone” and is released in large quantities during activities of bonding (such as sex, holding a baby, and yes, cuddling). As romantic relationships mature and move past basic physical attraction and lust, deeper, more stable bonds begin to form.
 
From an evolutionary perspective, lust, attraction, and attachment are all means to a single end: reproduction and the advancement of the human species. Each of these categories play a key role in the overall goal of reproduction, but unfortunately, these raw scientific definitions of love just scratch the surface of the ups and downs everyone goes through on the journey to a long-term relationship. In reality, lust, attraction, and attachment can be broken down further and reveal deeper social and psychological needs, and as many Hollywood romance movies can attest, the pathway from lust to long-term attachment can be a difficult voyage.
           
The initial stages of lust seem simple: a gentle touch, lingering eye contact, or telling a friend about your new crush leads to a rush of dopamine that begin the spiral of “falling in love.” From here, though, how the relationship progresses becomes increasingly complex. Fear of rejection, fear of commitment, or being overly needy are frequently called out as some of the main reasons why a relationship may not progress further. In many cases, psychological predispositions and past experience with various types of relationships can profoundly impact the bonds formed with a future romantic partner.
 
Research in this area tells us the initial bonds formed within a new romantic relationship are almost always influenced by the very first relationship we ever experience: the relationship with our parents. These early bonding experiences with our parents in infancy and toddlerhood shape how we perceive relationships and define what we view as a positive attachment. This Freudian approach to love and attachment may sound rudimentary, and many other researchers in the field argue that there are other explanations for the success of healthy attachment and how we define love. For example, a popular psychological theorist, Dr. Robert Sternberg, has proposed a whole new set of categories that define the stages of love. His initial work, published in 1986, presents the Triangular Theory of Love, which consists of intimacy, passion, and commitment. His love triangle (so to speak) is shown as the following model:

From this diagram, we can see the various combinations of different types of love, and how they are intertwined and related to one another. Unlike the pure biological basis of love described earlier, Dr. Sternberg presents the idea that love is a combination of different emotions that can occur simultaneously and is not only dictated by hormones and neurotransmitters. His ideas are rooted in the psychosocial construct of love, and he relies on the human need for social connection to describe various types of love.
 
The scientific definition of love and Dr. Sternberg’s definition of love are both right in their own respects. Simply describing love from a biological perspective does not fully encapsulate the intricacies of relationships and describing love exclusively from a psychosocial point of view does not consider the hard-wired evolutionary programming all humans are born with. As with all complex human constructs, the true meaning love is likely a combination of both definitions presented. With a deeply engrained biological need for sexual reproduction driven by hormones, combined with the need for social attachment and companionship, humans are capable of deeply emotional, romantic bonds that are unrivaled by other species.
 
Perhaps this is why love stories are the focal point of tales told throughout generations and are highlighted in great literary works and screenplays. Love, and the idea of love, often dominate many aspects of life and the successes and failures in the search for everlasting affection and attachment. It is no surprise that many of life’s greatest celebrations and deepest heartaches are born out of love.
 
Many often joke about the idea of Valentine’s Day being a “Hallmark” holiday and just a way for people to spend unnecessary money or time on fancy gifts or acts of affection. However, Valentine’s Day can also serve as a reminder to think about what love means to you. In your own relationships, whether romantic or otherwise, how do you define love? We would like to hear from you about what love means to you and continue to add on to the definitions presented here. Please feel free to share your thoughts on our website’s blog page or reach out to us on social media!

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