Body odor functions as an important chemosensory cue (a chemical signal perceived through smell) in human social communication and romantic relationships. Previous research has suggested that a romantic partner’s body odor may evoke feelings of comfort and social support, potentially influencing responses to stressful situations. However, whether these effects occur when partner odor is perceived outside conscious awareness has remained unclear. The present study examined how subconscious exposure to a romantic partner’s natural body odor affects subjective, physiological, and endocrine responses during psychosocial stress.
The researchers investigated whether subconsciously perceived partner odor could reduce stress responses in a manner similar to previously reported social support effects. Earlier studies had indicated that smelling a partner’s worn clothing might decrease perceived stress, although these findings could have been influenced by participants consciously recognizing the odor. To address this limitation, the authors aimed to determine whether partner odor presented below the threshold of conscious perception would influence perceived stress, heart rate, and cortisol release during the Trier Social Stress Test (TSST) (a standardized laboratory protocol used to induce psychosocial stress).
The study employed a randomized, double-blind, 2 × 2 between-participants design involving 179 individuals from heterosexual romantic relationships. Participants completed either the TSST or a non-stressful control condition while continuously receiving either their partner’s body odor or a neutral non-social control odor through a computerized olfactometer (a device that delivers odor stimuli under controlled conditions). Partner body odor was collected over five consecutive nights under standardized sampling procedures. Throughout the experiment, the investigators measured self-reported stress, salivary cortisol (a hormonal indicator of hypothalamic–pituitary–adrenal axis activation), and heart rate as an index of autonomic nervous system activity.
Contrary to the researchers’ original hypothesis, subconscious exposure to a romantic partner’s body odor did not reduce stress responses. Instead, participants in the partner-odor condition initially reported higher subjective stress levels than those in the control-odor condition, with this difference decreasing over time. Heart rate was also higher when partner odor was presented, particularly during the stress task. No significant effect of odor condition on cortisol responses was observed. Additional analyses indicated that heart rate increases were more pronounced among participants who rated their partner’s odor as highly sexually attractive, suggesting that attraction-related arousal may contribute to the observed heart rate pattern, although the underlying mechanism was not directly established. The authors further propose that the observed increase in perceived stress may reflect either a misattribution of attraction-related arousal to the stressful situation or an evolutionarily adaptive mechanism that enhances responsiveness when a loved one is potentially involved in a threatening context.
Overall, the findings indicate that subconscious chemosensory exposure to a romantic partner’s natural body odor did not reproduce the stress-buffering effects previously associated with conscious partner-related cues. Instead, the findings suggest that, under the experimental conditions studied, partner odor was associated with differences in subjective stress and heart rate, without a significant odor-related effect on cortisol responses. According to the authors, these results contribute to understanding how chemosensory signaling participates in social interaction and highlight the complexity of stress modulation by romantic partner cues. However, the sample was limited to individuals in heterosexual romantic relationships, and partner odor was not directly compared with the odor of another familiar or unfamiliar person. Further research is neededolkı to determine how broadly these findings apply.
Author: Ayşenur Güneş
Editor: Nehir Necem Ünlü
Reference: Spengler, M., et al. (2026). Smelling the romantic partner’s natural body odor increases psychological and autonomic but not cortisol stress responses. Scientific Reports, 16, Article 1760. https://doi.org/10.1038/s41598-025-27639-w