Theories and literature on the biopsychological dimensions of love

29 Nov

Theories and literature on the biopsychological dimensions of love: A broad exploration of evolutionary-developmental perspectives on romantic love, mirror neurons, interpersonal limbic synchronicity, neuroplastic interventions for trauma pathway resolution, and transpersonal ego death experiences


Alex Grey – The Kiss


Love, universal to the human condition, is the most profound human experience, and it is the most powerful drug. It comes in many forms, and impacts the brain in ways research is only recently beginning to probe. Love is not merely for pleasure, however. It is fundamental to human survival.

This is demonstrated through neuroimaging studies, but it is also apparent in the fact that love continues to prevail in world that is marked by extreme suffering and cruelty, as the world has been over the course of the millennia of human evolution. This paper will explore a broad literature review on the theories and research on love as necessary to human survival, and will present new frontiers in biopsychological research that may reveal exciting potentials for the future of our species.


It is impossible to demystify the powerful phenomenon of the experience of love in all its forms into merely a biological construct. The biopsychological correlates and the neural substrates of love are key to understanding it in its larger context, and scientific studies have only just begun to unravel these elemental mysteries that transcend even the human species.

For example, Harry Harlow’s famed monkey experiment showed that an infant monkey prefers the comforting feeling of a stuffed animal “mother” than the sustenance of food (Vicedo 2009). In this landmark study, results showed that the infants would rather love or be loved and go hungry than ensure their own survival but without the comfort of love. Attempts to explain love as a mechanism of survival fall short in the context of experiments like this. If the survival of one’s species is the paramount drive to all behavior, what could account for such actions?


Harry Harlow’s “The Nature of Love.”

This paper will attempt to explore the experience of love as essential to the human species in its survival over the millennia, and will also investigate love as a basic drive even when in conflict with survival itself. Love so often results in deeply painful experiences, which is also in conflict with a main human prerogative to pursue pleasure and avoid pain. What could account for the continued drive to find love, when by all accounts love can result in disaster?

The scientific inquiries into these age-old questions have begun to yield fascinating results that shed light not just on humanity’s past, but the potential for our future. Most promising of all is the research into mirror neurons (Lamm & Majdandžić 2015), limbic resonance (Lewis & Amini 2000), and the neuroplastic healing from trauma associated with loving transpersonal experiences (Szalavitz & Perry 2010). Perhaps love can save us all.

What is love?

One of the most interesting aspects of love is how it is universal to the human condition. While there are evolutionary developmental (evo-devo) perspectives on why love is essential to the survival of the human species (as well as some primates), many individuals construct personal mythological narratives about love. For example, some people believe that they were fated to meet and be together. What causes people to develop such bold beliefs regarding chance encounters? Perhaps it is the power of the transformational experience of love itself. It may feel so strong in our hearts, minds and bodies, that it activates a spiritual part of the brain (Brown 2012).


fMRI scans of brains in various stages of love

The brain itself is profoundly affected by love. Since one of the first fMRI studies on the cortical localization of love in 2004 (Tarlacı 2012), the brain’s reward center has been shown over and over again to be dramatically activated when the subject is reminded of the person they are in love with. All behaviors that activate the reward center are likely to create learned repetition, making love a conditioned stimulus and the subjective transformation experience a conditioned response.

This would provide some explanation for why humans continue to return to the search for love or an openness to it following deeply painful experiences produced by falling in love such as heartbreak and abandonment or betrayal. The conditioned response in the brain’s reward center may be a more physiologically powerful experience than the conditioned response of the grief of heartbreak. It is not yet fully understood why this may be the case, but the following may provide a clue.

Tarlacı’s 2004 study showed that the experience of seeing a photograph of the object of a subject’s passionate love resulted in the most dramatically significant activity in the A10 region of the ventral tegmental area (VTA) (Tarlacı 2012). This region of the brain, with the substantiva nigra, is the source of over 90 percent of the dopamine created in the brain (Tarlacı 2012). This is an extraordinarily powerful neurotransmitter combined with its impressively large production. Little wonder that love is a powerful drug. Given its universality in the human condition, across time, space, and cultures, it may be the most powerful in the history of humanity. Considering this power, it becomes understandable why so many mythologies are created both by the individual and collectively as cultures in order to explain the power of love in both a deeply personal and a social context.

Finally, to consider the consequences of high dopamine activity is to investigate the real potential human love has for our species, both as individuals in our central nervous system, as well as a civilization. The activity of reward stimuli is related to motivation, drive, goal-orientation, increased libido, wakefulness, and a general sense of wanting in the nervous system, as well as “novelty-seeking and creativity” (Tarlacı 2012). This is only slightly different from the pathological dopamine imbalance seen in people with schizophrenia and Parkinson’s, and others with a dysregulation of dopamine.

When in love, the interaction of dopamine with the pallidum, the caudal nucleus, the anterior cingulate cortex, the hypothalamus, the autonomic system, and the insular cortex are such that each area of the brain is more responsive and more efficient (Tarlacı 2012). Other studies have explored this in further detail, showing that cognitive performance can improve when the brain is reminded of the subject’s lover (Bianchi-Demicheli, Grafton & Ortigue 2006). If the experience of being in love is so powerful as a drug that it literally makes the brain more creative and improves many functions, it is logical that every living human would pursue and fantasize about finding this experience, especially if one has had it before, regardless of the cost.


Why we love

If love produces the ultimate drug-induced euphoria, it’s not hard to see the connection to the propagation of our species. It may not be accurate to say that love has always been mandatory for human survival, but it has evolved to be deeply connected to our survival as a species. From an evolutionary perspective, love’s connection to sex, and the associated experiences in the brain with both, is one of the most primary motivating factors for all people (as well as most non-human animals).

Mirror neurons are highly specialized brain cells that are designed to respond to others with empathy, altruism, understanding, and synchronization with others in such activities as sex, dancing, music, and any behavior that requires communication with others (particularly nonverbal) (Horstman 2011). Perhaps mirror neurons help to explain loneliness – the yearning for connection with others – as the essence of the eternal human condition, given that it is ingrained in our very physiology. Everyone has mirror neurons, though some more than others. A deficit in mirror neurons is associated with many types of mental illness and dysfunction, such as schizophrenia (Möhring et al 2015), autism spectrum disorders, personality disorders, sociopathy and psychopathy and more.


“Limbic Resonance” by Amanda Sage

An abundance of mirror neurons contributes to transpersonal experience, such as in the case of limbic resonance. Perhaps the most inspiring discovery in all of psychology research is as poetically romantic as it is scientifically invigorating. Building on Harlow’s research on physical loving comfort and cognitive-social development in baby monkeys (Harlow 1958) is the advancing theory of interpersonal limbic synchronicity, a label developed by the author of this paper to describe the following three distinct processes: limbic resonance, limbic regulation, and limbic revision (Lewis & Amini 2000). In limbic resonance, research has shown that our nervous systems and brain chemistry can interact without verbal communication, posing exciting possibilities in the future human communication, conflict resolution, deepening intimacy, and empathy studies (Schore 1994).

One example of this interaction would be eye contact between two people, whether between strangers who have just met and are experiencing chemistry, or twin siblings who merely need a look to “read” one another. This interaction can result in activation of both parties’ nervous systems, particularly the limbic system (Schore 1994), resulting in anything from increased heart rate to a shared spike in dopamine. Limbic regulation refers to a more long-term effect of how these interactions can influence our body systems and brain chemistry (Schore 1994), such as when living with a spouse of many years.


That is some serious limbic resonance going on. 

Finally, limbic revision refers to how these processes can be influenced with deliberate action in therapeutic contexts (Schore 1994). Such processes are part of a larger complex interplay at work in the resolution of trauma pathways for survivors of developmental trauma in the context of loving relationships (Szalavitz & Perry 2010). Furthermore, love can even alleviate the experience of both emotional and physical pain (Tarlacı 2012). Essentially, that love heals trauma in the brain.

We need love

If sex was the main motivating factor in life, and our species was only concerned with survival, love would probably not exist. The explanations for love, then, are concerned with a long-term nature to the need for our connections to sustain some longevity. Human offspring need an enormous amount of love, care, and energy in order to become independently viable adults. Fisher developed this idea as “the four-year itch,” (de Boer et al 2012). Romantic love allows for many of our sexual relationships to sustain this period in order to successfully produce offspring. Neuroimaging studies reveal that the brain’s reward centers, and their associated neural networks, activate dramatically when subjects view the face of their passionate love (Acevedo, Aron, Fisher & Brown 2012). This has an enormous evolutionary-developmental advantage to help sustain the commitment of both parents to the upbringing of their offspring.

Parenting in and of itself is responsible for the hard-wiring of the brain for specific types of love. The basis of attachment theory is that our adult relationships, and particularly romantic relationships, are rooted in our upbringing (Brown 2012). Much research is underway utilizing the new avenues of neuroimaging in the context of attachment theory and love, while major knowledge gaps remain. Research has shown that the brain circuits involved in mother-infant love as well as romantic love have large overlaps, with oxytocin and vasopressin playing the major neurotransmitter roles in both systems (de Boer et al 2012). Many therapists also report patterns of adults selecting romantic partners who replicate the function and/or dysfunction of their family of origin, likely due to its familiarity, known as the repetition compulsion (Holmes 2014).

Radical love

A radical form of love would be considered transpersonal in the sense that it is transcendent of a sense of the self. This is different from romantic love in that it is not individualistic in nature (concerned with survival and one’s genetic propagation) but is rather collectivistic (concerned with connection and community). This is a new frontier in both contemporary theory and practical research of biopsychology, especially in the exploration of concepts that are ancient in origin, such as from Eastern philosophy.


Carl Sagan and Ann Druyan. When they fell in love while working together on Voyager 1, she had her brain waves recorded while gazing at a photo of Sagan and transposed into sound that is now on the golden record itself. Infinite love. 

Campbell referred to ego death experience as self-surrender, or a form of transition when the self is transformed through the destruction of self-definition with replacement of a new self-identity (Limouze 2010). Jung called ego death psychic death, also referring to a personal transformation of the internal self (Jung 2015). Harlow’s own monkey experiment showed that love can transcend ego, or the self’s need to survive. Throughout the centuries, mythological narratives have centered on the theme of love triumphing over life, and passionate lovers sacrificing themselves in the ultimate to preserve their value of love and the object of their love. It is uncertain whether this is a form of ego death or a transpersonal experience of two selves merging in a way that research is beginning to illuminate in the neuroimaging of the brain in love.

Modern neuroscience’s new field of neurotheology explores the relationship between divine experience (a form of ego death) and cortical localization, as well as the similarities between divine experience and romantic love in the brain (Horstman 2011). Such ecstatic experiences are comparable with reports of psychedelic experience as well as orgasm and passionate love, and a rigorous study of them is necessary to understand the human potential to connect with each other, nurture empathy, and be more harmonious with each other and the Earth.

Perhaps the existence of these experiences, as well as the continued scientific investigation of them, is part of the essential human need to create meaning in a world and a universe that appear incomprehensibly vast. What could be more meaningful than the realization that humanity shares the same chemical makeup, not only with each other, but with the stars? Humanity has created creation myths over the course of history, but scientific research on the nature of the universe and the complex interplay of human brains are yielding fascinating insights into how we got here. It is the interpretation of the author of this paper that the ultimate meaning in our existence is that loving one another, specifically through the process of interpersonal limbic synchronicity (the most essential form of human connection), is the essence of our purpose in this world and this universe.

Among all species, humans are utterly unique in our ability to connect and love to this degree. To comprehend how we have come from compressed matter in the origin of the universe, to having distinct nervous systems which interact through eye contact with mother and child, and with lovers among lovers, is to realize the potential of love to conquer all the statistical odds that would have prevented us from being where we are now, with the ability to connect in the way that we do as humans.


Romantic love is the most powerful experience in the human condition, and new avenues of neuroimaging research are revealing its potential to facilitate the brain healing itself. Mirror neurons, interpersonal limbic synchronicity, and the study of transpersonal experiences, such as in tandem ego death (death of a sense of self shared by two or more individuals) are the frontier of biopsychology as it relates to the future of our species and civilization.

Further study is needed on these processes in the context of facilitated ego-death transpersonal experience, such as in psychedelic-assisted altered states of consciousness or meditative yoga nidra.

Over millennia, various spiritual experiences have been described in their respective canons regarding love in its highest forms – among two individuals, as well as among the individual and the cosmos or what some have called divinity. Further investigation is needed in order to illuminate the healing potential of the brain in the context of such transpersonal experiences.

Recent research into ego-diminishing experiences, such as the loss of a subjective self or self-identity, sheds light on the potential for a collectivistic shared loving experience that suggests a unity with others in a shared humanity as well as with the cosmos. A shared sense of togetherness is the epitome of transpersonal loving experience, and is one that is part of this thrilling frontier in the study of the biopsychology of human consciousness. 

These discoveries illuminate the shadows of previous mysteries that have been integral to the human experience, allowing us to better understand our past as a species. Finally, they provide compelling avenues for further research that will usher in the most exciting chapter in human history. What delight in contemplating our immense potential for healing and shared experience in these perilous and critical times to be human in this lifetime. 


Acevedo, B. P., Aron, A., Fisher, H. E., & Brown, L. L. (2012). Neural correlates of long-term intense romantic love. Social Cognitive And Affective Neuroscience, 7(2), 145-159. doi:10.1093/scan/nsq092

Bianchi-Demicheli, F., Grafton, S. T., & Ortigue, S. (2006). The power of love on the human brain. Social Neuroscience, 1(2), 90-103. doi:10.1080/17470910600976547

Brown, J. W. (2012). Love and Other Emotions: On the Process of Feeling. London: Karnac Books.

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, 201114-124. doi:10.1016/j.neuroscience.2011.11.017

Harlow, H. F. (1958). The nature of love. American Psychologist, 13(12), 673-685. doi:10.1037/ h0047884

Holmes, L. (2014). Reaching the repetition compulsion. Modern Psychoanalysis, 39(1), 26-37.

Horstman, J. (2011). The Scientific American Book of Love, Sex and the Brain : The Neuroscience of How, When, Why and Who We Love. Hoboken: Jossey-Bass.

Jung, Carl Gustav. (2015). Funk & Wagnalls New World Encyclopedia, 1p. 1.

Lamm, C., & Majdandžić, J. (2015). Review article: The role of shared neural activations, mirror neurons, and morality in empathy – A critical comment. Neuroscience Research, 90(Social Neuroscience), 15-24. doi:10.1016/j.neures.2014.10.008

Lewis, T., & Amini, F. (2000). A general theory of love. New York: Random House.

Limouze, H. S. (2010). Joseph Campbell. American National Biography (From Oxford University Press).

Möhring, N., Shen, C., Hahn, E., Ta, T. T., Dettling, M., & Neuhaus, A. H. (2015). Mirror neuron deficit in schizophrenia: Evidence from repetition suppression. Schizophrenia Research, 168174-179. doi:10.1016/j.schres.2015.07.035

Schore, A. (1994). Affect regulation and the origin of the self: the neurobiology of emotional development. Hillsdale, N.J.: L. Erlbaum Associates.

Szalavitz, M., & Perry, B. (2010). Born for love: Why empathy is essential– and endangered. New York: William Morrow.

Tarlacı, S. (2012). The Brain in Love: Has Neuroscience Stolen the Secret of Love?. Neuroquantology, 10(4), 744-753.

Vicedo, M. (2009). Mothers, machines, and morals: Harry Harlow’s work on primate love from lab to legend. Journal Of The History Of The Behavioral Sciences, 45(3), 193-218.

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