Biology of Attraction

by Dr Purnoor Kaur

“Love is an untamed force. When we try to control it, it destroys us...when we try to imprison it, it enslaves us...when we try to understand it, it leaves us feeling lost and confused.”

Paulo Coelho

Since time immemorial, the phenomenon of attraction has puzzled artists, musicians, philosophers, and scientists alike. The object of attraction may have furthered inquiry into the concept of beauty, thus, finds its way into human culture and language. Physical attractiveness has an evolutionary role to play, and features like facial symmetry are a marker of genetic quality. The Golden Ratio of Beauty in aesthetics helps us understand what makes something aesthetically pleasing and attractive. It was first described in 350 BC in Euclid’s Elements. It is a mathematical formula based on the Fibonacci sequence, which is a set of numbers where each number is the sum of the two preceding numbers. This ratio has been used for centuries to figure out what makes someone or something beautiful. It has been applied to many different aspects of beauty, including facial symmetry, body proportions, flowers and even non-living works of art.4 However, studies in line with the common understanding suggest that attraction is not based only on physical features, but also on personality traits, kindness and body language. Even the tone of someone’s voice can seem attractive to another.

In recent years, the terms like sapiosexuality and demisexuality have been gaining traction in the dating world. They refer to a person’s ability to be attracted to another based on their intellect or any such quality, rather than just physical appearance. Sapiosexuals are attracted to intelligence, while demisexuals are only able to form an emotional connection with someone after they have developed a strong bond. It is believed that humans are hardwired to be attracted to certain traits, such as intelligence and kindness. This attraction can manifest itself in different ways - from admiration of someone’s wit or wisdom to feeling a brain response when interacting with them. As we learn more about how humans form relationships and find romantic partners, it is becoming increasingly clear that these types of attractions can play an important role in our lives.

The chemical cocktail concerning attraction includes many neurotransmitters, chemical substances that are sent from one nerve cell (neuron) to another nerve cell through the space between two neurons (synapse). Neurotransmitters like dopamine, oxytocin, serotonin, and endorphins, often find a mention in self-help hacks. Dopamine is linked to motivation, reward and pleasure, and it also has a role to play in feelings of attraction. High levels of dopamine are usually noted in the initial stages of attraction, while oxytocin, known as the "love hormone", is involved in feelings of trust and attachment and is a key contributor to the feeling of love. Oxytocin is also released during physical contact and intimate relationships. Serotonin, another neurotransmitter, gives rise to feelings of contentment, calmness, and relaxation. High levels of serotonin correspond to the later stages of attraction, probably as the honeymoon phase settles. Endorphins are chemicals in the brain that are associated with feelings of pleasure and pain relief. They are often referred to as "feel-good" chemicals because they can produce feelings of happiness and euphoria. In the context of love, endorphins are thought to play a role in the feelings of happiness and attachment that people experience when they are in love. The release of endorphins during romantic experiences, such as physical touch, can help to reinforce the bond between partners and contribute to feelings of love and attachment.

(Image source - February 14, 2017, Love, Actually: The science behind lust, attraction, and companionship, Author - Katherine Wu, Figures by Tito Adhikary).

If we look at the overlapping concepts of lust, attraction, and attachment, these may be distinguished by their own set of hormones. Lust is dominated by instinctual tendencies based on spikes of sex hormones, whereas attraction brings about excitement and butterflies in the stomach in the early stages and is followed by the contentment of serotonin. Feelings of attachment follow the release of oxytocin.

Furthermore, love may as well be in the air. We may have underestimated the role of pheromones in humans, due to high reliance on visual and verbal cues in sociosexual context. However, when people get closer and become more intimate, it is likely that smell also plays a big role in many sociosexual behaviours. Recent studies do show that even if a smell is consciously not perceived, the sensation goes to the part of the brain responsible for conscious processing as well as the one responsible for emotional processing, communicating important evolutionary information.1

The actual cupid may be seated deep inside the brain which is linked with feelings of love. It is called the nucleus accumbens (ventral tegmental area) love is associated with the limbic system, which is composed of the hippocampus, amygdala, and cingulate cortex. The limbic system is involved in the processing of emotions and is also responsible for forming and storing memories. This is different from another part of the brain, the hypothalamus, responsible for controlling our instinctual drives and regulating basic biological functions.

Love and the instinctive drive to procreate or lust are two distinct emotions that have different motivations and outcomes. The instinctive drive to procreate is a biological instinct that is triggered by hormones and is the main purpose of reproduction. This drive is often associated with physical and sexual attraction. Love, on the other hand, is an emotion that is based on care, attachment, and understanding. It is an emotion that is often based on mutual respect and trust and is driven by the need for companionship and connection. Nevertheless, they are not mutually exclusive. Love can also include physical attraction, though it is not limited to it. Love is a complex emotion that encompasses many different aspects, including the physical, the mental, and the emotional. Both love and lust can exist together, and they can even intertwine.

Pragmatically driven people argue that love is a socially constructed emotion and is not real. However, it is difficult to deny the effects that love has on people and the strong emotions it can evoke. The world of love often dawns itself on the human mind with the first crush, usually during adolescence. It is the time of significant changes as the brain reaches a phase of development where a sense of autonomy and personal likes and dislikes start to form. In conjunction with hormonal changes during puberty, such as an increase in testosterone and oestrogen levels in males and females, respectively, there is a spark of sexual desire and attraction. Physical attraction can cause the release of adrenaline, which is often associated with the feeling of butterflies in the stomach. However, due to the incomplete development of the prefrontal cortex of the brain, rationale, decision-making, and impulse control are missing. This leaves the teenage heart susceptible to not only peer pressure but also the first heartbreak.

Approximate location of our inner cupid

Heartbreak, or the feeling of emotional pain after a romantic relationship ends, can have significant effects on the brain and body. For instance, the release of dopamine and oxytocin, two neurotransmitters associated with love and pleasure, will diminish significantly, leading to a decrease in feelings of attraction. Additionally, the nucleus accumbens may no longer be activated in the same way as before. Finally, levels of serotonin may also be reduced, instigating feelings of loneliness or emptiness. Simply put, a happy cocktail of chemicals shifts to new a sad mixture. Stress hormones can increase heart rate, blood pressure, and muscle tension. This response is known as the "fight or flight" response and is intended to help the body respond to stress or danger. All of this can cause physical symptoms, such as headaches, stomach aches, and increased sensitivity to physical pain. Heartbreak can also affect memory processes in the brain. For example, individuals may experience intense feelings of nostalgia and vivid memories of their past relationships. Additionally, there may be an increase in negative thoughts and intrusive memories, which can contribute to feelings of depression and anxiety. Sleep patterns alter and if the stress state lasts for a significant amount of time decrease in immune function may follow. While heartbreak can be a difficult experience, it can also provide opportunities for growth and self-reflection, and individuals often turn to art.

To navigate the uncharted sphere, there has been a simultaneous interest in psychological tactics. One notable one is a pattern of behaviour in which one person withdraws their interest or affection to create a sense of pursuit or desire in their partner. This can involve playing hard to get, being distant, or pulling away from the relationship, to make the other person work harder to win back their affection. Interestingly, results of a speed-dating study suggest playing hard to get hurt an affective (liking) response. However, when there is a psychological commitment, playing hard to get can boost a motivational (wanting) response. So, just like most people think, trying to be hard to get can sometimes work to get someone’s attention.2 In line with this, another popular adage suggests that physical separation can increase feelings of love and affection in a relationship. The idea behind this saying is that when people are apart from one another, they have time to reflect on their feelings and miss each other, which can deepen their emotional connection. One of the studies highlighted that when evaluating psychologically near targets, people may be attracted to them based on concrete details of the environment, such as how a target's behaviour affects how they feel about themselves at the moment. In addition to this, six studies found that when men were judging people who were emotionally far away from them, they were more attracted to women who were smarter than them. When targets were psychologically close, on the other hand, men were less interested in women who were smarter than them.3

Another long-standing trope in literature, film and television is the femme fatale and bad boy phenomenon. It is the idea that women are drawn to men who are dangerous or rebellious, while men are drawn to women who are mysterious or seductive. This attraction has been explored by many authors over the years, and it continues to fascinate people today. The concept of the femme fatale and the bad boy is rooted in our culture's fascination with the forbidden. We cannot help but be attracted to people who represent something that we know is wrong or dangerous. The idea of a femme fatale is especially appealing because it allows us to explore our desires without having to take any risks ourselves. Similarly, the bad boy appeals to us because he represents something exciting and daring that we may not have access to in our everyday lives. Shedding some light on this, contemporary psychologists like Jordan B. Peterson often discuss the subtext of dominance, competence and confidence, and the evolutionary value of these traits in the face of danger.

Approximate location of our inner cupid

If we were to base the entire argument of attraction and love on the need for procreation, same-sex attraction is counterintuitive. It does not offer an assurance of perpetuation of the family line or even the species in long term. One of the interesting ideas put forward by researchers is an attraction to the same sex as a means of sustaining social functions and intimacy among partners as a predominant cue rather than conception.5 However, the available research is limited. Sexual orientation, gender identity, and attraction are complex and multi-faceted aspects of human experience that are influenced by a range of factors, including biology, environment, and personal experiences. It is not yet clear whether these differences are innate or a result of environmental or experiential factors.

A famous quote by Bruce Lee sums up the ageing of attraction and love: “Love is like a friendship caught on fire. In the beginning a flame, very pretty, often hot and fierce, but still only light and flickering. As love grows older, our hearts mature and our love become as coals, deep-burning and unquenchable.” (“Bruce Lee - Love is like a friendship caught on fire. In...”) This idea can be extrapolated to how attraction matures with age. During adolescence, attraction kicks in like a tidal wave. But, in adulthood, the brain has fully developed and is better able to regulate emotions and impulses. Attraction in adulthood tends to be more stable and consistent, influenced by factors such as shared interests, values, and compatibility. Additionally, adults have more complex relationships and are better able to assess and make decisions about attraction. As the body gets older, attraction can continue to be stable but may be influenced by age-related changes. Decreased hormone levels, such as testosterone, can affect sexual desire and attraction. Additionally, age-related changes in brain activity and cognition can affect decision-making and perception, leading to different preferences and tendencies in attraction. Scientists have been successful in dissecting the underlying biological commotion to some extent, yet the work of Cupid cannot be fathomed.


1. Grammer K, Fink B, Neave N. Human pheromones and sexual attraction. Eur J Obstet Gynecol Reprod Biol. 2005 Feb 1;118(2):135–42.

2. Dai X, Dong P, Jia JS. When does playing hard to get increased romantic attraction? J Exp Psychol Gen. 2014: 143(2):521–6.

3. Park LE, Young AF, Eastwick PW. (Psychological) Distance Makes the Heart Grow Fonder: Effects of Psychological Distance and Relative Intelligence on Men’s Attraction to Women. Pers Soc Psychol Bull. 2015 Nov 1;41(11): 1459–73.

4. Mlacker S, Shah V V., Aldahan AS, McNamara CA, Alsaidan M, Nouri K. The Golden Ratio of Beauty-A Hidden Treasure. JAMA Dermatology. 2016 Jul 1;152(7): 828.

5. Barron AB, Hare B. Prosociality and a Sociosexual Hypothesis for the Evolution of Same-Sex Attraction in Humans. Front Psychol. 2019 Jan 16; 10.