Smell is one of several subtle cues that can influence sexual attraction, and science is beginning to explain why. While looks, values and behavior matter a lot, natural body scent may also carry information our brains quietly use when assessing compatibility.
What early studies suggested
In a well-known experiment from the 1990s, researcher Claude Wedekind asked men to wear cotton T-shirts for several days (no deodorant or fragrance). Women later smelled the shirts and tended to prefer the scent of men whose major histocompatibility complex (MHC)—a set of immune-related genes—was more dissimilar from their own. The idea is that pairing with someone who has a different immune profile could, in evolutionary terms, increase a child’s chance of broader disease resistance. If you’re curious about the biology, this short primer is helpful: NIH overview of HLA (MHC) genes.
Of course, scent is just one piece of the picture. Traits like warmth, reliability, and even cognitive or prosocial strengths can be just as influential in long-term attraction—see related research on why some women rate intelligence and generosity highly.
Important caveats
- Mixed evidence: Replications of MHC-based odor preferences show variability. Culture, diet, health, and environment can all sway how someone smells and how we perceive that scent.
- Timing and hormones: Some studies report that odor preferences can shift across the menstrual cycle. Hormonal contraception may also alter both body odor and odor preferences. Results are not uniform across individuals, so avoid drawing hard conclusions from a single “sniff test.”
- Orientation and diversity: Scent preferences and pair-bonding dynamics are diverse across individuals and relationships, including same-sex couples.
Practical takeaways
- Meet each other’s “real” scent: Spend relaxed, everyday time together without heavy fragrance use. Pay attention to how your partner smells after a workout or at the end of the day—that’s often the most informative natural scent.
- Treat scent as one signal, not a verdict: If a partner’s smell consistently feels pleasant and comforting, that can be a green flag. If it never feels right, that’s worth noting—but it shouldn’t outweigh core compatibility or respect.
- Context matters in relationships: Attraction can fluctuate in long-term partnerships. If you’re navigating questions like whether it’s normal to feel drawn to others, these reflections may help: Is It Ok To Fancy Other Women? And if your bond needs strengthening, practical skills (communication, empathy, shared routines) go a long way—see How To Save Your Marriage.
Bottom line: take a moment—literally—to breathe each other in. Natural scent can add useful data to everything else you’re learning about a person, but it’s most helpful when considered alongside character, health, and how you treat one another.