By Eva Selhub, MD
The nervous system invests in love as a biological strategy. The brain has one primary directive: maintain balance, or restore it as quickly as possible. Every physiological response the body generates — every hormone released, every immune cell deployed, every behavioral impulse activated — exists in service of that directive. Restored balance, or homeostasis, means safety to the brain. It means the organism is intact, the species will continue, all systems can return to their natural state of growth and repair. The entire human system — metabolic, nervous, cardiovascular, digestive — is organized around this goal.
What I have observed over thirty years of clinical practice, and what the science increasingly confirms, is that love in its many forms — connection to others, to something greater than ourselves, to our own inner life — induces a physiology that serves as one of the most powerful and efficient means the nervous system has to restore that balance. The Love Response® and the stress response are two sides of the same biological coin — one reflecting the presence of love, the other its absence. Both are normal. Both are necessary. The question is simply which one is running the show.
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The Stress Response
The stress response is one of the most elegant survival mechanisms biology has ever produced. Any challenge to the body’s balance — hunger, cold, emotional pain, physical exertion, a deadline, a difficult conversation — activates a cascade of hormones and physiological shifts designed to mobilize the organism and restore equilibrium. Most of the time, the system does exactly what it is supposed to do. The challenge arises, the response activates, balance is restored, the system settles. Hunger resolved by a meal. Exertion resolved by rest. Walter Cannon, the Harvard physiologist who first described this as the fight-or-flight response in 1915, understood it as the body’s emergency mobilization system — a coordinated discharge of the sympathetic nervous system preparing the organism to confront or escape a threat (Cannon, Bodily Changes in Pain, Hunger, Fear and Rage, 1915). Hans Selye expanded this framework two decades later, demonstrating that the physiological stress response is non-specific — that the body produces the same cascade of hormonal and physiological changes whether the threat is physical danger, emotional distress, or the accumulated pressure of daily demands (Selye, British Medical Journal, 1950).
The stress response becomes a threat response when the brain perceives that a challenge is not manageable — that the resources available to restore balance are insufficient. The key word is perceives. Before any conscious thought occurs, the brain is already making that assessment.
The reticular activating system, a network of neurons running through the brainstem, functions as the brain’s gatekeeper. Every piece of sensory information entering the body passes through it first. The RAS determines what gets attention and what gets filtered out, and when it registers something that may require a response, it passes that signal directly to the amygdala — the brain’s threat detection center — which then searches its stored emotional memory to determine how dangerous the situation is. This happens in milliseconds, long before the prefrontal cortex — the seat of rational thinking and complex decision making — has any opportunity to weigh in. By the time you are consciously aware of feeling threatened, the body is already flooded with cortisol and adrenaline, heart rate is climbing, digestion has slowed, muscles have tensed, and higher cognitive function has narrowed (Edlow et al., Neuroanatomy of the Human Ascending Arousal System, 2012).
What determines whether a stress becomes a threat is perception — specifically, the perception of manageability. And perception is shaped by everything that has come before: genetics, early life experience, the quality of available social support, cultural context, and the current state of the body’s own metabolic and inflammatory baseline. When faced with a challenge, the brain searches its memory bank for how similar challenges have been handled previously, what resources were available, and what the outcome was. If the record shows that resources were reliably there, the brain assesses the situation differently than if the record shows they were not. Two people facing the identical stressor may have entirely different physiological responses, because the amygdala is responding to memory and learned expectation as much as to present reality.
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How We Learn to Cope
To understand why perception matters so much, it helps to start with something simple. Hunger is a stress — a signal that the body’s balance has been disrupted and needs to be restored. The brain registers the disruption, activates the appropriate response, and motivates behavior. Food is found and eaten, balance is restored, and what the brain registers in that moment is relief — the direct physiological experience of homeostasis returning. This is the reward the nervous system is always seeking. It has nothing to do with pleasure in the abstract. It is the felt sense of equilibrium restored.
The brain learns from this. It encodes whatever produced that relief as a viable coping strategy, and the more reliably a behavior restores balance, the more deeply it becomes habituated. This encoding begins early in life, long before the prefrontal cortex is fully developed — a process that research confirms is not complete until the mid-twenties (Giedd, NIH; Steinberg, 2007). In the absence of mature cortical oversight, children develop coping strategies guided primarily by the amygdala and the emotional memory it is building in real time.
What makes this particularly significant is something Karim Nader’s landmark 2000 research at NYU revealed about how emotional memory actually works: every time a memory is recalled, it becomes temporarily labile — unstable and open to being updated before it reconsolidates (Nader, Schafe & LeDoux, Nature, 2000). Memories are not fixed recordings. They are living documents, rewritten slightly each time they are retrieved. When a child in a stressful environment recalls a past experience of feeling unsafe or unsupported, that memory is reactivated, the associated emotion fires, and the learned coping behavior — whatever previously produced relief — is reinforced and deepened. The cycle writes itself into the nervous system with each repetition, long before the child has the cortical capacity to evaluate whether the strategy is actually serving them.
Some of these strategies are adaptive. Hunger arises, food is sought, balance is restored. Other strategies develop in environments where straightforward need-meeting is unreliable — where an uncertain household, an emotionally unavailable parent, or early trauma teaches the nervous system to reach for whatever produces the fastest available relief, regardless of its long-term cost. A child who learns that food reliably produces comfort when emotional needs go unmet may carry that pattern into adulthood as stress eating. A child who learns that self-sufficiency is safer than asking for help may carry that into adulthood as an inability to receive support, even when support is precisely what the nervous system needs.
These habits are not character flaws. They are the nervous system doing exactly what it was designed to do — seeking the fastest available route back to balance with the resources and neural architecture it had at the time. The same memory lability that wrote those patterns in, however, is also what makes them available to be rewritten. The brain that learned fear can learn something else. And this is the beauty of neuroplasticity: reprogramming or new learning is not just a therapeutic promise, but a biological fact (McEwen, Annals of the New York Academy of Sciences, 1998).
On the flip side, this is also why most self-help strategies fail, and why habits — even ones a person genuinely wants to change — are so resistant to change. The coping patterns encoded early in life are not stored as conscious decisions that can be overridden by information or intention. They are stored as physiological responses, linked to emotional memory, and activated automatically by the amygdala before rational thinking has any opportunity to intervene. Reading about why a behavior is harmful does not reach the part of the nervous system running it. Neither does deciding, with great conviction, to stop. The prefrontal cortex can form an intention. It cannot, on its own, override a pattern that was encoded subcortically, reinforced through years of repetition, and tied to the body’s most fundamental drive — the restoration of balance. Real change requires working at the level where the pattern lives, which means working with the physiology, the emotional memory, and the body’s felt sense of safety — not just the thinking mind.
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The Love Response®
What the nervous system is reaching for, when the coping strategies fall short and the allostatic load keeps climbing, is not rest. Rest is necessary, and Herbert Benson’s research at Harvard demonstrated decades ago that the relaxation response — a state of deep physiological quiet achieved through meditative focus — produces measurable countereffects to the stress response. Heart rate slows, cortisol drops, the immune system regains function, higher cognitive processing returns (Benson & Klipper, The Relaxation Response, 1975). The body, given the conditions to do so, moves toward repair.
The Love Response® goes further. To understand why, it helps to look at what love actually does in the body at a neurochemical level. The dopaminergic reward system — the same circuitry involved in motivation, learning and the drive to seek what restores balance — activates in response to love and connection in ways that encode the experience as worth repeating. Recent research from Hebrew University reframes what dopamine is actually doing in this process: rather than signaling pleasure directly, dopamine mobilizes the organism toward what the nervous system has learned will restore equilibrium, while opioids provide the stabilizing signal — the physiological sense of relief — when that equilibrium is achieved (Cohen & Atzil, Neuroscience & Biobehavioral Reviews, 2026). Love is rewarding because it works — because it resolves the disruption and returns the system to balance more efficiently than almost anything else available to the nervous system.
Oxytocin, released through touch, eye contact, and the felt sense of safety and belonging, does something more specific still. It actively down-regulates the HPA axis — the hypothalamic-pituitary-adrenal stress response cascade — reducing cortisol, lowering blood pressure, dampening the inflammatory response, and shifting the autonomic nervous system toward the parasympathetic state where growth, repair and immune function are possible. It does this largely non-verbally, bypassing the thinking mind and speaking directly to the subcortical systems where the stress response originates. Endorphins released in states of love and connection reinforce this shift, encoding the physiological experience as a resolved challenge — balance restored — and deepening the nervous system’s inclination to reach for connection when under threat.
But the science, as precise as it is, only describes the mechanism. It does not fully account for what is actually being resolved when love does its work. What the nervous system is ultimately seeking, beneath the hormonal cascade and the autonomic shift, is a felt sense of wholeness — the experience of being enough, having enough, being wanted, being held by something larger than the isolated self. The stress response, in its deepest expression, is the physiology of separation. It is what the body does when it experiences itself as alone, insufficient, unsupported — a single drop of water cut off from its source. Every wisdom tradition that has ever grappled seriously with human suffering has named this as the root condition — the experience of separateness, of not enough, of unloved. Fear on one side, love on the other. The ocean on one side, the drop believing itself to be only a drop on the other.
The Love Response® is the physiological return to wholeness. It is the body’s way of remembering what it actually is.
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So What Does This Mean in Practical Terms?
It means that the infrastructure of your life — the quality of your relationships, your capacity to receive as well as give support, your relationship with something larger than yourself, whether that is nature, spirit, God, or simply the felt sense of being part of something beyond the isolated self, and the beliefs you carry about whether you are enough and worthy of being loved — these are not separate from your health, your resilience, or your capacity to function well under pressure. They are the biological substrate of all of it. They are what the nervous system draws on when it needs to return to balance.
Most people have never been taught to look there. They have been taught to manage symptoms, push through difficulty, optimize performance, and treat the body as a machine to be maintained. What thirty years of clinical practice showed me, again and again, is that the body does not work that way. It is a living system embedded in relationship — with other people, with nature, with something larger than itself — and it heals and thrives in proportion to the strength of those connections.
The first step, always, is awareness. The body is communicating constantly. Tension in the shoulders, tightness in the chest, the particular quality of exhaustion that sleep does not resolve, the low-grade anxiety that has been present so long it has become invisible — these are not inconveniences to be managed. They are signals. The nervous system’s way of saying that something in the balance has been disrupted and that the resources needed to restore it may not be sufficiently in place.
The next piece in this series goes into what the Love Response® actually is, how to recognize when you are in it and when you are not, and how to begin cultivating the conditions that allow the nervous system to access its most powerful regulatory strategy. For now, the most useful place to start is simply to pay attention — to what your body is telling you, and to what it may be reaching for.
