# Smelling the romantic partner’s natural body odor increases psychological and autonomic but not cortisol stress responses

## TL;DR

Smelling a romantic partner's body odor can increase stress and heart rate during stressful situations, but does not affect cortisol levels.

## Contribution

This study reveals that partner body odor can amplify psychological and autonomic stress responses, contrary to expectations.

## Key findings

- Partner body odor increased subjective stress and heart rate during a stress test.
- Partner body odor did not influence cortisol levels.
- The stress amplification may be due to misattributed arousal or evolutionary adaptation.

## Abstract

While social support from romantic partners is known to ameliorate stress responses, it remains unclear whether perceiving a partner’s body odor can elicit similar stress-buffering effects. In this study, 179 participants living in heterosexual romantic relationships underwent either the Trier Social Stress Test (TSST) or a non-stressful control condition while being exposed to their partner’s body odor (collected under standardized conditions over five consecutive nights) or a neutral, non-social control odor presented via an olfactometer. The partner’s odor had no effect on cortisol release. However, contrary to previous findings, subconsciously smelling one’s own partner increased subjective stress and heart rates. Potential underlying mechanisms include the causal misattribution of attraction-related, arousal-induced heart rate increases to the stressful experimental situation, or an evolutionarily adaptive mechanism that amplifies stress responses when a loved one is potentially involved in the threatening situation.

The online version contains supplementary material available at 10.1038/s41598-025-27639-w.