The Limits of Chemistry

Chemistry is often treated as a decisive force in romantic life. When it is present, people feel justified in leaning in. When it is absent, even after a pleasant and promising date, interest tends to stall. Chemistry appears to offer clarity, but what it actually provides is something
narrower: an early signal, powerful in its immediacy, yet limited in what it can reliably tell us. Most people recognise this tension intuitively. They know chemistry matters, but they also sense that it does not explain everything that makes a relationship viable or sustaining. And
yet, in practice, chemistry is frequently asked to carry more authority than it deserves, shaping decisions about who to pursue, who to dismiss, and how long to remain invested.
What is chemistry?
In relationship research, romantic chemistry is recognised as a multifaceted, emergent experience. It can include attraction, emotional connection, interactive engagement, and a sense of mutual responsiveness. Importantly, chemistry is not viewed as a fixed trait residing
in one person, but as something that arises between two people through interaction. When researchers examine how people themselves describe chemistry, however, a more specific pattern emerges. A recent qualitative study published in Behavioral Sciences, found that while participants acknowledged chemistry could involve multiple elements, the most commonly cited and immediately recognised experience was an instantaneous spark - a felt sense of connection, intensity, or attraction early in an interaction, rather than a gradual assessment of compatibility or emotional safety (Devenport et al., 2025).
Why the spark feels so convincing
That immediate spark carries weight because it is physiological as much as psychological. Early romantic chemistry is associated with activation of the brain’s reward and motivation systems, including increased dopamine and norepinephrine, which are neurochemicals
involved in focus, pursuit, and salience. The body feels energised, attention narrows, and the other person begins to stand out in a way that feels meaningful. This response is not irrational. From an evolutionary perspective, rapid bonding had
adaptive value. From a learning perspective, our nervous systems are shaped by repeated relational experiences. Attachment research helps explain why this kind of activation can feel meaningful so quickly. Our nervous systems learn through experience what closeness feels like, and over time they become efficient at recognising familiar patterns. When past intimacy involved emotional
intensity or heightened engagement, the body may respond swiftly to similar cues, even before conscious evaluation has a chance to catch up. (Mikulincer et al., 2020). 1Chemistry, then, is neither imagined nor accidental. But it is also not a verdict. It is a signal
that arrives early and speaks loudly.
When chemistry starts doing more than it should
Problems arise when chemistry shifts from being an opening signal to becoming the deciding
factor. When people over-index on chemistry, two familiar patterns tend to emerge. In one, the absence of chemistry limits pursuit. Dates can go well. Conversation can flow. The other person may be emotionally available, respectful, even aligned with what someone
says they want. And yet, without chemistry, interest stalls. Many people describe this not as rejection, but as resignation: “I know they’re good for me, but I don’t feel anything.” The relationship does not end; it simply never begins. In other cases, the opposite happens. A relationship starts with strong chemistry. People invest quickly and overlook early warning signs. That initial pull shapes the decision to begin the relationship and continues to guide it even if doubts surface. Concerns are registered, but they carry less weight. Over time, it becomes clear how much chemistry has been steering judgment from the beginning. Because the nervous system is activated, the mind
works to maintain coherence, often finding reasons to persist rather than pause. In both cases, chemistry is doing more work than it should either preventing people from staying curious enough for other forms of connection to develop or pulling people forward
too quickly.
What chemistry can and cannot tell you
Research consistently shows that long-term relationship satisfaction is far more strongly predicted by responsiveness, repair after conflict, and emotional attunement than by early intensity alone (Overall & Lemay, 2021). Chemistry does not reliably predict these capacities. Chemistry can tell you that your system is activated, your attention is engaged, and something feels compelling or familiar. What it cannot tell you is how conflict will be handled, whether needs will be met consistently, or whether emotional safety will deepen or erode over time. From a nervous-system perspective, this distinction matters. Stephen Porges’ work on Polyvagal Theory describes how the autonomic nervous system continuously scans for cues of safety and threat, shaping whether we feel socially open, vigilant, or withdrawn. When systems are accustomed to high arousal, intensity can be misread as connection and calm can register as disinterest. In such cases, chemistry reflects nervous-system conditioning more than relational compatibility (Porges, 2022). 2The consequences of over-indexing on chemistry often appear later, in hindsight. When chemistry dominates judgment, it can obscure both warning signs and possibilities.
Chemistry as one voice among others
A more grounded way to relate to chemistry is to treat it as one voice in a larger conversation. It deserves attention, but it should not be allowed to dominate the discussion or determine the outcome on its own. Qualities such as emotional safety, mutual responsiveness, values alignment, and repair after conflict tend to speak more slowly. They require time and exposure to reveal themselves. When chemistry drowns them out, decisions are made with incomplete information. Wanting chemistry is not the problem. The issue arises when it is allowed to outweigh every other form of relational information. Chemistry can open the door, spark curiosity, and make
connection feel alive, but sustaining love depends on quieter, more consistent signals - emotional presence, repair, respect, and reliability over time. The goal is not to mute the spark, but to place it in context. Chemistry speaks loudly, but wisdom often emerges only after the initial intensity had time to settle.

References
Devenport, L., et al. (2025). Exploring lay understandings of romantic chemistry. Behavioral
Sciences, MDPI. https://www.mdpi.com/3592440
Mikulincer, M., Shaver, P. R., & Ein-Dor, T. (2020). Attachment orientations and emotion
regulation in close relationships. Current Opinion in Psychology, 25, 86–91.
Overall, N. C., & Lemay, E. P. (2021). Attachment, responsiveness, and well-being in romantic
relationships. Current Opinion in Psychology, 43, 110–115.
Porges, S. W. (2022). Polyvagal theory: A science of safety. Frontiers in Integrative
Neuroscience, 16, 871227. https://doi.org/10.3389/fnint.2022.871227
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