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Home / Equine Research Bank / PLoS One / Human emotional odours influence horses’ behaviour and...
PloS one2026; 21(1); e0337948; doi: 10.1371/journal.pone.0337948

Human emotional odours influence horses’ behaviour and physiology.

Abstract: Olfaction is the most widespread sensory modality animals use to communicate, yet much remains to be discovered about its role. While most studies focused on intraspecific interactions and reproduction, new evidence suggests chemosignals may influence interspecific interactions and emotional communication. This study explores this possibility, investigating the potential role of olfactory signals in human-horse interactions. Cotton pads carrying human odours from fear and joy contexts, or unused pads (control odour) were applied to 43 horses' nostrils during fear tests (suddenness and novelty tests) and human interaction tests (grooming and approach tests). Principal component analysis showed that overall, when exposed to fear-related human odours, horses exhibited significantly heightened fear responses and reduced interaction with humans compared to joy-related and control odours. More precisely, when exposed to fear-related odours, horses touched the human less in the human approach test (effect size: Rate Ratio(RR)=0.60 ± 0.24), gazed more at the novel object (RR = 1.32 ± 0.14), and were more startled (startle intensity - Cohen's d = -0.88 ± 0.39; and maximum heart rate - Cohen's d = 1.16 ± 0.47) by a sudden event. These results highlight the significance of chemosignals in interspecific interactions and provide insights into questions about the impact of domestication on emotional communication. Moreover, these findings have practical implications regarding the significance of handlers' emotional states and its transmission through odours during human-horse interactions.
Copyright: © 2026 Jardat et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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Publication Date: 2026-01-14 PubMed ID: 41533708PubMed Central: PMC12803465DOI: 10.1371/journal.pone.0337948Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

Overview

  • This study investigates how human emotional odors, specifically fear and joy, influence the behavior and physiological responses of horses during various tests.
  • The research found that horses exposed to fear-related human odors showed increased fear behaviors and reduced positive interactions compared to those exposed to joy-related or control odors.

Introduction to the Research

  • Olfaction (sense of smell) is a critical sensory modality for animal communication.
  • Most previous research focused on how smell impacts communication within the same species (intraspecific) and reproductive behaviors.
  • New evidence suggests olfactory signals also play a role in communication across different species (interspecific), particularly related to emotions.
  • This study specifically explores how human emotional odors affect horse behavior, which is important for understanding human-animal interactions and domestication effects.

Methodology

  • Samples:
    • Cotton pads were used to collect human odors from contexts evoking fear and joy.
    • Unused cotton pads served as a control odor.
  • Participants: 43 horses.
  • Tests conducted:
    • Fear tests:
      • Suddenness test – measuring startle responses to unexpected events.
      • Novelty test – measuring reaction to new objects.
    • Human interaction tests:
      • Grooming test.
      • Approach test – measuring how horses physically interact with humans.
  • The cotton pads with the different odors were applied to the horses’ nostrils to ensure direct olfactory exposure.

Key Findings

  • Exposure to fear-related human odors caused significant behavioral and physiological changes in horses:
    • Horses exhibited heightened fear responses overall.
    • Decrease in positive interactions — notably, horses touched humans less during the approach test (Rate Ratio (RR) = 0.60 ± 0.24), meaning a 40% reduction compared to joy or control odors.
    • Increased attention and vigilance towards novel objects (RR = 1.32 ± 0.14), indicating more gaze time at unfamiliar stimuli.
    • Heightened startle responses to sudden events:
      • Greater startle intensity (Cohen’s d = -0.88 ± 0.39).
      • Increased maximum heart rate (Cohen’s d = 1.16 ± 0.47), suggesting elevated physiological arousal.
  • Joy-related and control odors did not provoke such fear-related responses, indicating specificity of the fear odor effect.
  • Principal component analysis was used to capture overall behavioral and physiological trends across the tests.

Implications and Significance

  • The research confirms that olfactory signals from humans can influence horses’ emotional states and behavior.
  • Highlights the importance of interspecific emotional communication mediated by smell, beyond just visual or auditory cues.
  • Provides insight into how domestication might have shaped emotional communication channels between humans and horses.
  • Practical relevance:
    • Handlers’ emotional states can be chemically transmitted to horses via odor, potentially affecting horse behavior and welfare.
    • Understanding these signals might improve safety and bond quality in human-horse interactions by managing handler emotions.

Concluding Remarks

  • This study demonstrates a clear link between human emotional odors and changes in horse behavior and physiological responses during fear and human interaction scenarios.
  • It broadens our understanding of how animals interpret human emotional cues through olfaction, an often-overlooked sensory modality in human-animal communication research.
  • Future research may explore how these findings extend to other domesticated animals and different human emotional states.

Cite This Article

APA
Jardat P, Destrez A, Damon F, Tanguy-Guillo N, Lainé AL, Parias C, Reigner F, Ferreira VHB, Calandreau L, Lansade L. (2026). Human emotional odours influence horses’ behaviour and physiology. PLoS One, 21(1), e0337948. https://doi.org/10.1371/journal.pone.0337948

Publication

PloS one
ISSN: 1932-6203
NlmUniqueID: 101285081
Country: United States
Language: English
Volume: 21
Issue: 1
Pages: e0337948
PII: e0337948

Researcher Affiliations

Jardat, Plotine
  • Institut Français du Cheval et de l'Equitation, Pôle développement, Innovation et Recherche, Nouzilly, France.
  • INRAE, CNRS, Université de Tours, PRC, Nouzilly, France.
Destrez, Alexandra
  • Development of Olfactory Communication and Cognition Laboratory, Centre des Sciences du GoÛt et de l'Alimentation, Institut Agro Dijon, CNRS, Université de Bourgogne-Franche-Comté, Inrae, Dijon, France.
Damon, Fabrice
  • Development of Olfactory Communication and Cognition Laboratory, Centre des Sciences du GoÛt et de l'Alimentation, Institut Agro Dijon, CNRS, Université de Bourgogne-Franche-Comté, Inrae, Dijon, France.
Tanguy-Guillo, Noa
  • INRAE, CNRS, Université de Tours, PRC, Nouzilly, France.
Lainé, Anne-Lyse
  • INRAE, CNRS, Université de Tours, PRC, Nouzilly, France.
Parias, Céline
  • INRAE, CNRS, Université de Tours, PRC, Nouzilly, France.
Reigner, Fabrice
  • UEPAO, INRAE, Nouzilly, France.
Ferreira, Vitor H B
  • INRAE, CNRS, Université de Tours, PRC, Nouzilly, France.
Calandreau, Ludovic
  • INRAE, CNRS, Université de Tours, PRC, Nouzilly, France.
Lansade, Léa
  • INRAE, CNRS, Université de Tours, PRC, Nouzilly, France.

MeSH Terms

  • Horses / physiology
  • Animals
  • Humans
  • Behavior, Animal / physiology
  • Emotions / physiology
  • Fear / physiology
  • Odorants
  • Male
  • Female
  • Smell / physiology

Conflict of Interest Statement

The authors declare no competing interests.

References

This article includes 85 references
  1. Baeckens S. Evolution of animal chemical communication: Insights from non-model species and phylogenetic comparative methods. Belg J Zool 2019;149.
    doi: 10.26496/bjz.2019.31google scholar: lookup
  2. Mason RT, Parker MR. Social behavior and pheromonal communication in reptiles. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2010;196(10):729–49.
    doi: 10.1007/s00359-010-0551-3pubmed: 20585786google scholar: lookup
  3. Woodley SK. Pheromonal communication in amphibians. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2010;196(10):713–27.
    doi: 10.1007/s00359-010-0540-6pubmed: 20526605google scholar: lookup
  4. Jesseau SA, Holmes WG, Lee TM. Mother–offspring recognition in communally nesting degus, Octodon degus. Anim Behav 2008;75(2):573–82.
    doi: 10.1016/j.anbehav.2007.06.015google scholar: lookup
  5. Bánszegi O, Jacinto E, Urrutia A, Szenczi P, Hudson R. Can but don’t: olfactory discrimination between own and alien offspring in the domestic cat. Anim Cogn 2017;20(4):795–804.
    doi: 10.1007/s10071-017-1100-zpubmed: 28540504google scholar: lookup
  6. Richard F-J, Hunt JH. Intracolony chemical communication in social insects. Insect Soc 2013;60(3):275–91.
    doi: 10.1007/s00040-013-0306-6google scholar: lookup
  7. Kochetkov VV. The Wolf (Canis lupus L.): territory or habitat. Biol Bull Rev 2023;13(S3):S321–8.
    doi: 10.1134/s2079086423090074google scholar: lookup
  8. Stankowich T. Armed and dangerous: predicting the presence and function of defensive weaponry in mammals. Adapt Behav 2011;20(1):32–43.
    doi: 10.1177/1059712311426798google scholar: lookup
  9. Buchinger TJ, Siefkes MJ, Zielinski BS, Brant CO, Li W. Chemical cues and pheromones in the sea lamprey (Petromyzon marinus). Front Zool 2015;12:32.
    doi: 10.1186/s12983-015-0126-9pmc: PMC4658815pubmed: 26609313google scholar: lookup
  10. Boissy A, Terlouw C, Le Neindre P. Presence of cues from stressed conspecifics increases reactivity to aversive events in cattle: evidence for the existence of alarm substances in urine. Physiol Behav 1998;63(4):489–95.
    doi: 10.1016/s0031-9384(97)00466-6pubmed: 9523888google scholar: lookup
  11. Vieuille-Thomas C, Signoret JP. Pheromonal transmission of an aversive experience in domestic pig. J Chem Ecol 1992;18(9):1551–7.
    doi: 10.1007/BF00993228pubmed: 24254286google scholar: lookup
  12. Calvi E, Quassolo U, Massaia M, Scandurra A, D’Aniello B, D’Amelio P. The scent of emotions: a systematic review of human intra- and interspecific chemical communication of emotions. Brain Behav 2020;10(5):e01585.
    doi: 10.1002/brb3.1585pmc: PMC7218249pubmed: 32212329google scholar: lookup
  13. Loos HM, Schaal B, Pause BM, Smeets MAM, Ferdenzi C, Roberts SC. Past, present, and future of human chemical communication research. Perspect Psychol Sci 2025;20(1):20–44.
    doi: 10.1177/17456916231188147pmc: PMC11720269pubmed: 37669015google scholar: lookup
  14. de Groot JHB, Smeets MAM, Rowson MJ, Bulsing PJ, Blonk CG, Wilkinson JE. A sniff of happiness. Psychol Sci 2015;26(6):684–700.
    doi: 10.1177/0956797614566318pubmed: 25870406google scholar: lookup
  15. de Groot JHB, Haertl T, Loos HM, Bachmann C, Kontouli A, Smeets MAM. Unraveling the universality of chemical fear communication: evidence from behavioral, genetic, and chemical analyses. Chem Senses 2023;48:bjad046.
    doi: 10.1093/chemse/bjad046pmc: PMC10718800pubmed: 37944028google scholar: lookup
  16. Smeets MAM, Rosing EAE, Jacobs DM, van Velzen E, Koek JH, Blonk C. Chemical fingerprints of emotional body odor.. Metabolites 2020;10(3):84.
    doi: 10.3390/metabo10030084pmc: PMC7142800pubmed: 32121157google scholar: lookup
  17. de Groot JHB, Smeets MAM, Kaldewaij A, Duijndam MJA, Semin GR. Chemosignals communicate human emotions.. Psychol Sci 2012;23(11):1417–24.
    doi: 10.1177/0956797612445317pubmed: 23019141google scholar: lookup
  18. Parr-Cortes Z, Müller CT, Talas L, Mendl M, Rooney NJ. Does the odour of human stress or relaxation affect dogs’ cognitive bias?. 2024.
    doi: 10.21203/RS.3.RS-4142530/V1pmc: PMC11263577pubmed: 39039125google scholar: lookup
  19. Siniscalchi M, d’Ingeo S, Quaranta A. The dog nose “KNOWS” fear: asymmetric nostril use during sniffing at canine and human emotional stimuli.. Behav Brain Res 2016;304:34–41.
    doi: 10.1016/j.bbr.2016.02.011pubmed: 26876141google scholar: lookup
  20. D’Aniello B, Semin GR, Alterisio A, Aria M, Scandurra A. Interspecies transmission of emotional information via chemosignals: from humans to dogs (Canis lupus familiaris).. Anim Cogn 2018;21(1):67–78.
    doi: 10.1007/s10071-017-1139-xpubmed: 28988316google scholar: lookup
  21. Destrez A, Costes-Thiré M, Viart A-S, Prost F, Patris B, Schaal B. Male mice and cows perceive human emotional chemosignals: a preliminary study.. Anim Cogn 2021;24(6):1205–14.
    doi: 10.1007/s10071-021-01511-6pubmed: 33839953google scholar: lookup
  22. Rørvang MV, Nielsen BL, McLean AN. Sensory abilities of horses and their importance for equitation science.. Front Vet Sci 2020;7:633.
    doi: 10.3389/fvets.2020.00633pmc: PMC7509108pubmed: 33033724google scholar: lookup
  23. Saslow CA. Understanding the perceptual world of horses.. Appl Anim Behav Sci 2002;78(2–4):209–24.
    doi: 10.1016/s0168-1591(02)00092-8google scholar: lookup
  24. Péron F, Ward R, Burman O. Horses (Equus caballus) discriminate body odour cues from conspecifics.. Anim Cogn 2014;17(4):1007–11.
    doi: 10.1007/s10071-013-0717-9pubmed: 24305997google scholar: lookup
  25. Krueger K, Flauger B. Olfactory recognition of individual competitors by means of faeces in horse (Equus caballus).. Anim Cogn 2011;14(2):245–57.
    doi: 10.1007/s10071-010-0358-1pubmed: 21132447google scholar: lookup
  26. Lansade L, Colson V, Parias C, Trösch M, Reigner F, Calandreau L. Female horses spontaneously identify a photograph of their keeper, last seen six months previously.. Sci Rep 2020;10(1):6302.
    doi: 10.1038/s41598-020-62940-wpmc: PMC7156667pubmed: 32286345google scholar: lookup
  27. Lansade L, Colson V, Parias C, Reigner F, Bertin A, Calandreau L. Human face recognition in horses: data in favor of a holistic process.. Front Psychol 2020;11:575808.
    doi: 10.3389/fpsyg.2020.575808pmc: PMC7522352pubmed: 33041946google scholar: lookup
  28. Trösch M, Bertin E, Calandreau L, Nowak R, Lansade L. Unwilling or willing but unable: can horses interpret human actions as goal directed?. Anim Cogn 2020;23(5):1035–40.
    doi: 10.1007/s10071-020-01396-xpubmed: 32449047google scholar: lookup
  29. Smith AV, Proops L, Grounds K, Wathan J, Scott SK, McComb K. Domestic horses (Equus caballus) discriminate between negative and positive human nonverbal vocalisations.. Sci Rep 2018;8(1):13052.
    doi: 10.1038/s41598-018-30777-zpmc: PMC6115467pubmed: 30158532google scholar: lookup
  30. Smith AV, Proops L, Grounds K, Wathan J, McComb K. Functionally relevant responses to human facial expressions of emotion in the domestic horse (Equus caballus).. Biol Lett 2016;12(2):20150907.
    doi: 10.1098/rsbl.2015.0907pmc: PMC4780548pubmed: 26864784google scholar: lookup
  31. Proops L, Grounds K, Smith AV, McComb K. Animals remember previous facial expressions that specific humans have exhibited.. Curr Biol 2018;28(9):1428-1432.e4.
    doi: 10.1016/j.cub.2018.03.035pubmed: 29706519google scholar: lookup
  32. Schrimpf A, Single M-S, Nawroth C. Social referencing in the domestic horse.. Animals (Basel) 2020;10(1):164.
    doi: 10.3390/ani10010164pmc: PMC7022515pubmed: 31963699google scholar: lookup
  33. Trösch M, Cuzol F, Parias C, Calandreau L, Nowak R, Lansade L. Horses categorize human emotions cross-modally based on facial expression and non-verbal vocalizations.. Animals (Basel) 2019;9(11):862.
    doi: 10.3390/ani9110862pmc: PMC6912773pubmed: 31653088google scholar: lookup
  34. Jardat P, Liehrmann O, Reigner F, Parias C, Calandreau L, Lansade L. Horses discriminate between human facial and vocal expressions of sadness and joy.. Anim Cogn 2023;26(5):1733–42.
    doi: 10.1007/s10071-023-01817-7pubmed: 37543956google scholar: lookup
  35. Nakamura K, Takimoto-Inose A, Hasegawa T. Cross-modal perception of human emotion in domestic horses (Equus caballus).. Sci Rep 2018;8(1):8660.
    doi: 10.1038/s41598-018-26892-6pmc: PMC6013457pubmed: 29930289google scholar: lookup
  36. Sabiniewicz A, Tarnowska K, Świątek R, Sorokowski P, Laska M. Olfactory-based interspecific recognition of human emotions: Horses (Equus ferus caballus) can recognize fear and happiness body odour from humans (Homo sapiens).. Appl Anim Behav Sci 2020;230:105072.
    doi: 10.1016/j.applanim.2020.105072google scholar: lookup
  37. Jardat P, Destrez A, Damon F, Menard-Peroy Z, Parias C, Barrière P. Horses discriminate human body odors between fear and joy contexts in a habituation-discrimination protocol.. Sci Rep 2023;13(1):3285.
    doi: 10.1038/s41598-023-30119-8pmc: PMC9968287pubmed: 36841856google scholar: lookup
  38. Poutaraud A, Guilloteau L, Gros C, Lobstein A, Meziani S, Steyer D. Lavender essential oil decreases stress response of horses.. Environ Chem Lett 2017;16(2):539–44.
    doi: 10.1007/s10311-017-0681-8google scholar: lookup
  39. Lansade L, Bouissou M-F, Erhard HW. Fearfulness in horses: a temperament trait stable across time and situations.. Appl Anim Behav Sci 2008;115(3–4):182–200.
    doi: 10.1016/j.applanim.2008.06.011google scholar: lookup
  40. Lansade L, Pichard G, Leconte M. Sensory sensitivities: components of a horse’s temperament dimension.. Appl Anim Behav Sci 2008;114(3–4):534–53.
    doi: 10.1016/j.applanim.2008.02.012google scholar: lookup
  41. Lansade L, Nowak R, Lainé A-L, Leterrier C, Bonneau C, Parias C. Facial expression and oxytocin as possible markers of positive emotions in horses.. Sci Rep 2018;8(1):14680.
    doi: 10.1038/s41598-018-32993-zpmc: PMC6168541pubmed: 30279565google scholar: lookup
  42. Percie du Sert N, Hurst V, Ahluwalia A, Alam S, Avey MT, Baker M. The ARRIVE guidelines 2.0: updated guidelines for reporting animal research.. PLoS Biol 2020;18(7):e3000410.
    doi: 10.1371/journal.pbio.3000410pmc: PMC7360023pubmed: 32663219google scholar: lookup
  43. Sinister (VF) - YouTube. Wild Bunch SA; 2012. Available from: https://www.youtube.com/watch?v=7tSVThDrUsE&t=4838s
  44. Lansade L, Trösch M, Parias C, Blanchard A, Gorosurreta E, Calandreau L. Horses are sensitive to baby talk: pet-directed speech facilitates communication with humans in a pointing task and during grooming.. Anim Cogn 2021;24(5):999–1006.
    doi: 10.1007/s10071-021-01487-3pubmed: 33738670google scholar: lookup
  45. Cognie J, Freret S, Lansade L, Parias C, Barriere P, Gesbert A. Early castration in foals: consequences on physical and behavioural development.. Equine Vet J 2023;55(2):214–21.
    doi: 10.1111/evj.13580pubmed: 35478462google scholar: lookup
  46. von Borell E, Langbein J, Després G, Hansen S, Leterrier C, Marchant J. Heart rate variability as a measure of autonomic regulation of cardiac activity for assessing stress and welfare in farm animals -- a review.. Physiol Behav 2007;92(3):293–316.
    doi: 10.1016/j.physbeh.2007.01.007pubmed: 17320122google scholar: lookup
  47. R Core Team. R: a Language and Environment for Statistical Computing.. Vienna, Austria: R Foundation for Statistical Computing; 2021.
  48. Wickham H. Ggplot2: Elegant graphics for data analysis.. Springer International Publishing; 2016.
  49. Kassambara A, Mundt F. factoextra: Extract and visualize the results of multivariate data analyses; 2020.. .
  50. Brooks ME, Kristensen K, van Benthem KJ, Magnusson A, Berg CW, Nielsen A. {glmmTMB} balances speed and flexibility among packages for zero-inflated generalized linear mixed modeling.. R J 2017;9:378–400.
  51. Hartig F. DHARMa: residual diagnostics for hierarchical (multi-level/ mixed) regression models; 2021.. .
  52. Fox J, Weisberg S. An {R} companion to applied regression.. Thousand Oaks (CA): Sage; 2019.
  53. Lenth RV. emmeans: Estimated marginal means, aka least-squares means; 2022.. .
  54. Wei T, Simko V. R package “corrplot”: visualization of a correlation matrix; 2021.. .
  55. Bohák Z, Szabó F, Beckers J-F, Melo de Sousa N, Kutasi O, Nagy K. Monitoring the circadian rhythm of serum and salivary cortisol concentrations in the horse.. Domest Anim Endocrinol 2013;45(1):38–42.
    doi: 10.1016/j.domaniend.2013.04.001pubmed: 23688596google scholar: lookup
  56. Adriaense JEC, Koski SE, Huber L, Lamm C. Challenges in the comparative study of empathy and related phenomena in animals.. Neurosci Biobehav Rev 2020;112:62–82.
    doi: 10.1016/j.neubiorev.2020.01.021pubmed: 32001272google scholar: lookup
  57. Pérez-Manrique A, Gomila A. Emotional contagion in nonhuman animals: a review.. Wiley Interdiscip Rev Cogn Sci 2022;13(1):e1560.
    doi: 10.1002/wcs.1560pmc: PMC9285817pubmed: 33951303google scholar: lookup
  58. Pause BM, Adolph D, Prehn-Kristensen A, Ferstl R. Startle response potentiation to chemosensory anxiety signals in socially anxious individuals.. Int J Psychophysiol 2009;74(2):88–92.
    doi: 10.1016/j.ijpsycho.2009.07.008pubmed: 19666058google scholar: lookup
  59. Prehn A, Ohrt A, Sojka B, Ferstl R, Pause BM. Chemosensory anxiety signals augment the startle reflex in humans.. Neurosci Lett 2006;394(2):127–30.
    doi: 10.1016/j.neulet.2005.10.012pubmed: 16257486google scholar: lookup
  60. Lübke KT, Busch A, Hoenen M, Schaal B, Pause BM. Chemosensory anxiety signals prime defensive behavior in prepubertal girls.. Physiol Behav 2017;173:30–3.
    doi: 10.1016/j.physbeh.2017.01.035pubmed: 28119156google scholar: lookup
  61. d’Ingeo S, Quaranta A, Siniscalchi M, Stomp M, Coste C, Bagnard C. Horses associate individual human voices with the valence of past interactions: a behavioural and electrophysiological study.. Sci Rep 2019;9(1):11568.
    doi: 10.1038/s41598-019-47960-5pmc: PMC6689011pubmed: 31399629google scholar: lookup
  62. Mendl M, Burman OHP, Paul ES. An integrative and functional framework for the study of animal emotion and mood.. Proc Biol Sci 2010;277(1696):2895–904.
    doi: 10.1098/rspb.2010.0303pmc: PMC2982018pubmed: 20685706google scholar: lookup
  63. Kret ME, Massen JJM, de Waal FBM. My fear is not, and never will be, your fear: on emotions and feelings in animals.. Affect Sci 2022;3(1):182–9.
    doi: 10.1007/s42761-021-00099-xpmc: PMC9382921pubmed: 36042781google scholar: lookup
  64. Keltner D, Kring AM. Emotion, social function, and psychopathology.. Rev Gen Psychol 1998;2(3):320–42.
    doi: 10.1037/1089-2680.2.3.320google scholar: lookup
  65. Boissy A. Fear and fearfulness in animals.. Q Rev Biol 1995;70(2):165–91.
    doi: 10.1086/418981pubmed: 7610234google scholar: lookup
  66. Jardat P, Lansade L. Cognition and the human-animal relationship: a review of the sociocognitive skills of domestic mammals toward humans. Anim Cogn 2022;25(2):369–84.
    doi: 10.1007/s10071-021-01557-6pubmed: 34476652google scholar: lookup
  67. Nawroth C, Albuquerque N, Savalli C, Single M-S, McElligott AG. Goats prefer positive human emotional facial expressions. R Soc Open Sci 2018;5(8):180491.
    doi: 10.1098/rsos.180491pmc: PMC6124102pubmed: 30225038google scholar: lookup
  68. Galvan M, Vonk J. Man’s other best friend: domestic cats (F. silvestris catus) and their discrimination of human emotion cues. Anim Cogn 2016;19(1):193–205.
    doi: 10.1007/s10071-015-0927-4pubmed: 26400749google scholar: lookup
  69. Albuquerque N, Guo K, Wilkinson A, Savalli C, Otta E, Mills D. Dogs recognize dog and human emotions. Biol Lett 2016;12(1):20150883.
    doi: 10.1098/rsbl.2015.0883pmc: PMC4785927pubmed: 26763220google scholar: lookup
  70. Quaranta A, d’Ingeo S, Amoruso R, Siniscalchi M. Emotion recognition in cats. Animals (Basel) 2020;10(7):1107.
    doi: 10.3390/ani10071107pmc: PMC7401521pubmed: 32605256google scholar: lookup
  71. Wilkins AS, Wrangham RW, Fitch WT. The “domestication syndrome” in mammals: a unified explanation based on neural crest cell behavior and genetics. Genetics 2014;197(3):795–808.
    doi: 10.1534/genetics.114.165423pmc: PMC4096361pubmed: 25024034google scholar: lookup
  72. Ferreira VHB, Lansade L, Calandreau L, Cunha F, Jensen P. Are domesticated animals dumber than their wild relatives? A comprehensive review on the domestication effects on animal cognitive performance. Neurosci Biobehav Rev 2023;154:105407.
    doi: 10.1016/j.neubiorev.2023.105407pubmed: 37769929google scholar: lookup
  73. Hare B, Brown M, Williamson C, Tomasello M. The domestication of social cognition in dogs. Science 2002;298(5598):1634–6.
    doi: 10.1126/science.1072702pubmed: 12446914google scholar: lookup
  74. McKinley J, Sambrook TD. Use of human-given cues by domestic dogs ( Canis familiaris ) and horses ( Equus caballus ). Anim Cogn 2000;3(1):13–22.
    doi: 10.1007/s100710050046google scholar: lookup
  75. Wilson C, Campbell K, Petzel Z, Reeve C. Dogs can discriminate between human baseline and psychological stress condition odours. PLoS One 2022;17(9):e0274143.
    doi: 10.1371/journal.pone.0274143pmc: PMC9518869pubmed: 36170254google scholar: lookup
  76. D’Aniello B, Fierro B, Scandurra A, Pinelli C, Aria M, Semin GR. Sex differences in the behavioral responses of dogs exposed to human chemosignals of fear and happiness. Anim Cogn 2021;24(2):299–309.
    doi: 10.1007/s10071-021-01473-9pmc: PMC8035118pubmed: 33459909google scholar: lookup
  77. Mormède P, Andanson S, Aupérin B, Beerda B, Guémené D, Malmkvist J. Exploration of the hypothalamic-pituitary-adrenal function as a tool to evaluate animal welfare. Physiol Behav 2007;92(3):317–39.
    doi: 10.1016/j.physbeh.2006.12.003pubmed: 17234221google scholar: lookup
  78. Kang O-D, Lee W-S. Changes in salivary cortisol concentration in horses during different types of exercise. Asian-Australas J Anim Sci 2016;29(5):747–52.
    doi: 10.5713/ajas.16.0009pmc: PMC4852239pubmed: 26954193google scholar: lookup
  79. Rolls ET. Emotion explained. Oxford University Press 2005.
    doi: 10.1093/acprof:oso/9780198570035.001.0001google scholar: lookup
  80. Liehrmann O, Cosnard C, Riihonen V, Viitanen A, Alander E, Jardat P. What drives horse success at following human-given cues? An investigation of handler familiarity and living conditions. Anim Cogn 2023;26(4):1283–94.
    doi: 10.1007/s10071-023-01775-0pmc: PMC10113126pubmed: 37072511google scholar: lookup
  81. Gomes N, Benrós MF, Martins JS, Semin GR. Sweating it out: the influence of sex and emotions on human sweat production. Biol Psychol 2025;201:109125.
    doi: 10.1016/j.biopsycho.2025.109125pubmed: 40935280google scholar: lookup
  82. Roberts SC, Třebická Fialová J, Sorokowska A, Langford B, Sorokowski P, Třebický V. Emotional expression in human odour. Evol Hum Sci 2022;4:e44.
    doi: 10.1017/ehs.2022.44pmc: PMC10426192pubmed: 37588919google scholar: lookup
  83. Mitro S, Gordon AR, Olsson MJ, Lundström JN. The smell of age: perception and discrimination of body odors of different ages. PLoS One 2012;7(5):e38110.
    doi: 10.1371/journal.pone.0038110pmc: PMC3364187pubmed: 22666457google scholar: lookup
  84. Katsuyama M, Narita T, Nakashima M, Kusaba K, Ochiai M, Kunizawa N. How emotional changes affect skin odor and its impact on others. PLoS One 2022;17(6):e0270457.
    doi: 10.1371/journal.pone.0270457pmc: PMC9246182pubmed: 35771844google scholar: lookup
  85. Havlíček J, Fialová J, Roberts SC. Individual variation in body odor. In: Buettner A, editor. Springer handbook of odor. Cham: Springer International Publishing 2017. p. 125–6.
    doi: 10.1007/978-3-319-26932-0_50google scholar: lookup

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