The neurobiological basis of attachment｜how the brain relates to others

Attachment is a fascinating and fundamental concept, which has not only captivated the interest of psychologists, but also opened up new perspectives in several disciplines such as biology. This article explores the neurobiological basis of attachment and its implications, drawing on the work of pioneers such as John Bowlby, Harry Harlow and Konrad Lorenz. Discovering these mechanisms can be essential for those considering training in massage therapy, as it highlights the impact of touch and the caring relationship on human connection and well-being.

The foundations of attachment

Attachment is a deep emotional bond that unites two individuals, enabling protection and harmonious development. This bond is not unique to humans; it also occurs in many animals. As early as the 1930s, Lorenz observed that ducklings followed him everywhere after they hatched. This imprinting phenomenon in birds is a short period after birth when chicks don’t know who their parent is, and attach themselves to the first thing they see. This work has shown that attachment is a biological function with adaptive value, promoting survival by protecting against external dangers.

In humans, this bond is vital to the infant’s development. The famous British psychologist John Bowlby has shown that children have a natural tendency to attach themselves to a protective figure in order to feel secure. This early connection influences future relationships and psychological well-being throughout life.

Attachment hormones: oxytocin and vasopressin

Recent advances in neuroscience have led to a better understanding of the role of certain hormones in the development of attachment. Oxytocin and vasopressin, two neuropeptides produced in the hypothalamus, play an essential role in the formation of social bonds. Oxytocin, often referred to as the “bonding hormone”, is released during physical contact, reinforcing feelings of closeness and reducing stress. This hormone is particularly active during childbirth and breastfeeding, promoting the bond between mother and child. It is also secreted by fathers when in contact with their infants.

In mammals, as in humans, oxytocin reduces fear reactions and stimulates maternal behavior. For example, studies on ewes show that injection of oxytocin induces strong, selective attachment to their offspring. In monogamous rodents, such as voles, oxytocin and vasopressin are involved in pair bonding, playing a distinct but complementary role in males and females.

Attachment and stress

Attachment isn’t just about emotional bonds; it’s also an important regulator of stress. Studies on voles show that stress can strengthen social bonds in males, while inhibiting them in females. This is partly explained by the way stress affects levels of oxytocin, one of the hormones that acts directly on stress-related neural circuits.

In fact, it helps to calm stress responses. In rats, for example, oxytocin administration reduces levels of cortisol, the stress hormone, and promotes a state of calm. This ability of attachment to alleviate stress is one of the foundations of its role in emotional well-being, an aspect particularly relevant to massage therapy, where gentle, intentional touch can help reduce stress and create a sense of security.

When attachment is disrupted in the first few moments of life, stress is observed to cause a remodeling of neuronal architecture in key areas of the brain, with greater risk of developing addictive behaviors, depression, anxiety, memory, learning, immune or metabolic disorders.

Attachment and pleasure

In addition to regulating stress, attachment activates the brain’s reward system, a circuit that reinforces behaviors essential for survival by providing pleasure. This system, which notably involves dopamine, is the same one that is activated when experiencing positive emotions, satisfying primary needs, or social interaction.

In voles, vasopressin receptors in certain areas of the brain promote monogamous behavior. This same circuit is involved in the pleasure experienced during social contact and touching, reinforcing the bond of attachment. In humans, this reward system is activated by physical contact, notably during massage, where the release of oxytocin and activation of dopaminergic circuits contribute to a deep and lasting sense of well-being.

Touch therapy

Understanding the neurobiology of attachment enables massage therapy practitioners to go beyond simple physical techniques to foster an empathic connection with their clients. Touch is not just about tissue manipulation, but can also strengthen attachment bonds and activate soothing neurobiological responses.

Thus, therapeutic massage can not only relieve physical pain, but also promote a state of emotional well-being by reducing stress levels and stimulating the brain’s pleasure circuits. Clients, often in search of security and comfort, find massage therapy a safe space where touch plays a fundamental role in emotional healing.

Conclusion

Attachment is a pillar of mental and emotional health. Thanks to discoveries about oxytocin and vasopressin, it’s now clear that emotional bonds are not just abstract concepts, but are rooted in biology. As future massage therapists, understanding the neurobiological basis of attachment enables us to appreciate how touch positively influences stress regulation and pleasure-seeking. This knowledge enriches practice by reinforcing empathic and relational foundations, offering clients more than just a physical treatment, but a path to overall well-being.

To remember:

• Attachment is an emotional connection essential to development and survival, playing an important role in emotional well-being from birth.
• Oxytocin and vasopressin: These hormones, produced by the brain, support attachment and social bonds by reducing stress and reinforcing feelings of closeness.
• Attachment helps regulate stress and activates the reward system, promoting positive emotions and satisfaction.
• In massage therapy, touch can promote a lasting, soothing and reassuring state of well-being for clients by acting on the same circuits that regulate stress.

Sources :

• Gorka AX, Hanson JL, Radtke SR, Hariri AR. Reduced hippocampal and medial prefrontal gray matter mediate the association between reported childhood maltreatment and trait anxiety in adulthood and predict sensitivity to future life stress. Biol Mood Anxiety Disord. 2014 Nov 13;4:12. doi: 10.1186/2045-5380-4-12. PMID: 25408863; PMCID: PMC4236295.
• Lambert, N. et Lotstra, F. (2005) . L’attachement. De Konrad Lorenz à Larry Young : de l’éthologie à la neurobiologie. Cahiers critiques de thérapie familiale et de pratiques de réseaux, no 35(2), 83-97. https://doi.org/10.3917/ctf.035.0083.
• Nowak, R., & Boivin, X. (2014). Filial attachment in sheep: Similarities and differences between ewe-lamb and human-lamb relationships. Applied Animal Behaviour Science, 164, 12–28. https://doi.org/10.1016/j.applanim.2014.09.013
• Sheridan M.A. , Fox N.A., Zeanah C.H., McLaughlin K.A., Nelson C.A., Variation in neural development as a result of exposure to institutionalization early in childhood, Proc. Natl. Acad. Sci. U.S.A.109 (32) 12927-12932, https://doi.org/10.1073/pnas.1200041109 (2012).
• Van Harmelen, A., Van Tol, M., Dalgleish, T., Van Der Wee, N. J. A., Veltman, D. J., Aleman, A., Spinhoven, P., Penninx, B. W. J. H., & Elzinga, B. M. (2014). Hypoactive medial prefrontal cortex functioning in adults reporting childhood emotional maltreatment. Social Cognitive and Affective Neuroscience, 9(12), 2026–2033. https://doi.org/10.1093/scan/nsu008
• Vicedo, M. (2009). The father of ethology and the foster mother of ducks: Konrad Lorenz as expert on motherhood. Isis, 100(2), 263–291. https://doi.org/10.1086/599553