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PloS one2017; 12(5); e0176717; doi: 10.1371/journal.pone.0176717

Are horses capable of mirror self-recognition? A pilot study.

Abstract: Mirror Self-Recognition (MSR) unveils complex cognitive, social and emotional skills and it has been found only in humans and few other species, such as great apes, dolphins, elephants and magpies. In this pilot study, we tested if horses show the capacity of MSR. Four subjects living socially under naturalistic conditions were selected for the experiment. We adopted the classical mark test, which consists in placing a coloured mark on an out-of-view body part, visible only through mirror inspection. If the animal considers the image as its own, it will use its reflection to detect the mark and will try to explore it. We enhanced the classical paradigm by introducing a double-check control. Only in the presence of the reflecting surface, animals performed tactile and olfactory exploration of the mirror and looked behind it. These behaviors suggest that subjects were trying to associate multiple sensory cues (visual, tactile and olfactory) to the image in the mirror. The lack of correspondence between the collected stimuli in front of the mirror and the response to the colored mark lead us to affirm that horses are able to perceive that the reflected image is incongruent when compared with the memorized information of a real horse. However, without replication of data, the self-directed behavior towards the colored marks showed by our horses cannot be sufficient per se to affirm that horses are capable of self-recognition.
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Publication Date: 2017-05-16 PubMed ID: 28510577PubMed Central: PMC5433687DOI: 10.1371/journal.pone.0176717Google 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.

The research explores whether horses have mirror self-recognition (MSR) abilities, a cognitive skill found in few species, by using a mark test under naturalistic conditions. The results suggest horses may perceive incongruities between a reflected image and their information about a real horse, but self-recognition cannot be definitively confirmed without further data replication.

About the Research

The study focused on investigating the potential for MSR in horses. MSR is a cognitive skill that indicates an animal’s capacity to recognize its own reflection in a mirror. This ability presents complex cognitive, social, and emotional skills and has previously only been noted in humans and a few other species like elephants, dolphins, and magpies.

  • The researchers selected four horses that lived under naturalistic social conditions for their pilot study.
  • They applied the classical mark test, which implied placing a coloured mark on a body part of an animal that could only be seen through mirror inspection. If an animal perceives the image as its own, it will examine the mark via its reflection.
  • The researchers enhanced the traditional mark test by adding a ‘double-check’ control.

Key Findings and Interpretations

  • The horses only performed tactile and olfactory exploration of the mirror and looked behind it when a reflecting surface was present. This behaviour suggests that the horses tried to associate multiple sensory cues – visual, tactile, and olfactory – with the image in the mirror.
  • The collected data indicated a lack of correspondence between the horses’ stimuli in front of the mirror and the response to the coloured mark. From this, the researchers inferred that the horses could perceive that the reflected image was incongruent when compared with their memorized information of a real horse.

Limits of the Study

The researchers caution that, owing to the limitations of their pilot study, these findings should be interpreted with caution. They admitted that the self-directed behaviour towards the coloured marks displayed by the horses is not sufficient in itself to definitively assert that horses are capable of self-recognition. More data replication is needed for conclusive evidence of horses possessing MSR.

Cite This Article

APA
Baragli P, Demuru E, Scopa C, Palagi E. (2017). Are horses capable of mirror self-recognition? A pilot study. PLoS One, 12(5), e0176717. https://doi.org/10.1371/journal.pone.0176717

Publication

PloS one
ISSN: 1932-6203
NlmUniqueID: 101285081
Country: United States
Language: English
Volume: 12
Issue: 5
Pages: e0176717
PII: e0176717

Researcher Affiliations

Baragli, Paolo
  • Dipartimento di Scienze Veterinarie, Università di Pisa, Pisa, Italy.
  • Museo di Storia Naturale, Università di Pisa, Calci, Italy.
Demuru, Elisa
  • Museo di Storia Naturale, Università di Pisa, Calci, Italy.
Scopa, Chiara
  • Dipartimento di Scienze Veterinarie, Università di Pisa, Pisa, Italy.
  • Museo di Storia Naturale, Università di Pisa, Calci, Italy.
Palagi, Elisabetta
  • Museo di Storia Naturale, Università di Pisa, Calci, Italy.
  • Unità di Primatologia Cognitiva, ISTC-CNR, Roma, Italy.

MeSH Terms

  • Animals
  • Behavior, Animal
  • Horses
  • Pilot Projects
  • Recognition, Psychology
  • Visual Perception

Conflict of Interest Statement

The authors have declared that no competing interests exist.

References

This article includes 60 references
  1. Outram AK, Stear NA, Bendrey R, Olsen S, Kasparov A, Zaibert V, Thorpe N, Evershed RP. The earliest horse harnessing and milking.. Science 2009 Mar 6;323(5919):1332-5.
    doi: 10.1126/science.1168594pubmed: 19265018google scholar: lookup
  2. Liljenstolpe C. Horses in Europe Uppsala. Lönnell C, editor. Swedish University of Agricultural Sciences; 2009. w.wbfsh.org/files/EU%20Equus%202009.pdf.
  3. Cirulli F, Borgi M, Berry A, Francia N, Alleva E. Animal-assisted interventions as innovative tools for mental health.. Ann Ist Super Sanita 2011;47(4):341-8.
    pubmed: 22194067doi: 10.4415/ann_11_04_04google scholar: lookup
  4. Whalen CN, Case-Smith J. Therapeutic effects of horseback riding therapy on gross motor function in children with cerebral palsy: a systematic review.. Phys Occup Ther Pediatr 2012 Aug;32(3):229-42.
    doi: 10.3109/01942638.2011.619251pubmed: 22122355google scholar: lookup
  5. Lanata A, Guidi A, Valenza G, Baragli P, Scilingo EP. Quantitative heartbeat coupling measures in human-horse interaction.. Annu Int Conf IEEE Eng Med Biol Soc 2016 Aug;2016:2696-2699.
    pubmed: 28268877doi: 10.1109/embc.2016.7591286google scholar: lookup
  6. Lovrovich P, Sighieri C, Baragli P. Following human-given cues or not? Horses (Equus caballus) get smarter and change strategy in a delayed three choice task. Appl Anim Behav Sci 2015;166: 80–88.
  7. Hanggi EB, Ingersoll JF. Long-term memory for categories and concepts in horses (Equus caballus).. Anim Cogn 2009 May;12(3):451-62.
    doi: 10.1007/s10071-008-0205-9pubmed: 19148689google scholar: lookup
  8. Proops L, McComb K, Reby D. Cross-modal individual recognition in domestic horses (Equus caballus).. Proc Natl Acad Sci U S A 2009 Jan 20;106(3):947-51.
    doi: 10.1073/pnas.0809127105pmc: PMC2630083pubmed: 19075246google scholar: lookup
  9. Proops L, McComb K. Cross-modal individual recognition in domestic horses (Equus caballus) extends to familiar humans.. Proc Biol Sci 2012 Aug 22;279(1741):3131-8.
    pmc: PMC3385734pubmed: 22593108doi: 10.1098/rspb.2012.0626google scholar: lookup
  10. Sankey C, Henry S, André N, Richard-Yris MA, Hausberger M. Do horses have a concept of person?. PLoS One 2011 Mar 30;6(3):e18331.
    doi: 10.1371/journal.pone.0018331pmc: PMC3068175pubmed: 21479184google scholar: lookup
  11. Wathan J, McComb K. The eyes and ears are visual indicators of attention in domestic horses.. Curr Biol 2014 Aug 4;24(15):R677-9.
    doi: 10.1016/j.cub.2014.06.023pmc: PMC4123162pubmed: 25093554google scholar: lookup
  12. Briefer EF, Maigrot AL, Mandel R, Freymond SB, Bachmann I, Hillmann E. Segregation of information about emotional arousal and valence in horse whinnies.. Sci Rep 2015 Apr 21;4:9989.
    doi: 10.1038/srep09989pmc: PMC4404681pubmed: 25897781google scholar: lookup
  13. Wathan J, Burrows AM, Waller BM, McComb K. EquiFACS: The Equine Facial Action Coding System.. PLoS One 2015;10(8):e0131738.
    doi: 10.1371/journal.pone.0131738pmc: PMC4526551pubmed: 26244573google scholar: lookup
  14. 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 Feb;12(2):20150907.
    doi: 10.1098/rsbl.2015.0907pmc: PMC4780548pubmed: 26864784google scholar: lookup
  15. Cozzi A, Sighieri C, Gazzano A, Nicol CJ, Baragli P. Post-conflict friendly reunion in a permanent group of horses (Equus caballus).. Behav Processes 2010 Oct;85(2):185-90.
    doi: 10.1016/j.beproc.2010.07.007pubmed: 20659538google scholar: lookup
  16. Broom DM. Cognitive ability and awareness in domestic animals and decisions about obligations to animals. Appl Anim Behav Sci 2010;126(1): 1–11.
  17. Anderson JR, Gallup GG Jr. Which primates recognize themselves in mirrors?. PLoS Biol 2011 Mar;9(3):e1001024.
    doi: 10.1371/journal.pbio.1001024pmc: PMC3046971pubmed: 21390247google scholar: lookup
  18. Suddendorf T, Butler DL. The nature of visual self-recognition.. Trends Cogn Sci 2013 Mar;17(3):121-7.
    pubmed: 23410584doi: 10.1016/j.tics.2013.01.004google scholar: lookup
  19. Anderson JR, Gallup GG Jr. Mirror self-recognition: a review and critique of attempts to promote and engineer self-recognition in primates.. Primates 2015 Oct;56(4):317-26.
    pubmed: 26341947doi: 10.1007/s10329-015-0488-9google scholar: lookup
  20. Gallup GG Jr. Toward a comparative psychology of mind. In: Mellgren RL, editor. Animal cognition and behavior. New York: North-Holland; 1983. pp. 473–510.
  21. de Waal FB. The thief in the mirror.. PLoS Biol 2008 Aug 19;6(8):e201.
    pmc: PMC2517621pubmed: 18715116doi: 10.1371/journal.pbio.0060201google scholar: lookup
  22. de Waal FB. Putting the altruism back into altruism: the evolution of empathy.. Annu Rev Psychol 2008;59:279-300.
    pubmed: 17550343doi: 10.1146/annurev.psych.59.103006.093625google scholar: lookup
  23. Gallop GG Jr. Chimpanzees: self-recognition.. Science 1970 Jan 2;167(3914):86-7.
    pubmed: 4982211doi: 10.1126/science.167.3914.86google scholar: lookup
  24. Bischof-Köhler D. Empathy and self-recognition in phylogenetic and ontogenetic perspective. Emot Rev 2012;4(1): 40–48.
  25. Povinelli DJ, Gallup GG Jr, Eddy TJ, Bierschwale DT, Engstrom MC, Perilloux HK. Chimpanzees recognize themselves in mirrors. Anim Behav 1997;53: 1083–1088.
  26. Suárez SD, Gallup GG. Self-recognition in chimpanzees and orangutans, but not gorillas. J Hum Evol 1981;10: 175–188.
  27. Westergaard GC, Hyatt CW. The responses of bonobos (Pan paniscus) to their mirror images: evidence of self-recognition. Hum Evol 1994;9: 273–279.
  28. Allen M, Schwartz BL. Mirror self-recognition in a gorilla (Gorilla gorilla gorilla). J Integr Biosci 2008;5(1): 19–24.
  29. Chang L, Fang Q, Zhang S, Poo MM, Gong N. Mirror-induced self-directed behaviors in rhesus monkeys after visual-somatosensory training.. Curr Biol 2015 Jan 19;25(2):212-217.
    doi: 10.1016/j.cub.2014.11.016pubmed: 25578908google scholar: lookup
  30. Toda K, Platt ML. Animal cognition: monkeys pass the mirror test.. Curr Biol 2015 Jan 19;25(2):R64-R66.
    pubmed: 25602304doi: 10.1016/j.cub.2014.12.005google scholar: lookup
  31. Plotnik JM, de Waal FB, Reiss D. Self-recognition in an Asian elephant.. Proc Natl Acad Sci U S A 2006 Nov 7;103(45):17053-7.
    doi: 10.1073/pnas.0608062103pmc: PMC1636577pubmed: 17075063google scholar: lookup
  32. Reiss D, Marino L. Mirror self-recognition in the bottlenose dolphin: a case of cognitive convergence.. Proc Natl Acad Sci U S A 2001 May 8;98(10):5937-42.
    doi: 10.1073/pnas.101086398pmc: PMC33317pubmed: 11331768google scholar: lookup
  33. Prior H, Schwarz A, Güntürkün O. Mirror-induced behavior in the magpie (Pica pica): evidence of self-recognition.. PLoS Biol 2008 Aug 19;6(8):e202.
    doi: 10.1371/journal.pbio.0060202pmc: PMC2517622pubmed: 18715117google scholar: lookup
  34. McAfee LM, Mills DS, Cooper JJ. The use of mirrors for the control of stereotypic weaving behaviour in the stabled horse. Appl Anim Behav Sci 2002;78(2): 159–173.
  35. Mills DS, Davenport K. Evidence for the importance of visual stimuli in the control of equine weaving behaviour. Anim Sci 2002;74: 95–101.
  36. Kay R, Hall C. The use of a mirror reduces isolation stress in horses being transported by trailer. Appl Anim Behav Sci 2009;116(2): 237–243.
  37. Piller CA, Stookey JM, Watts JM. Effects of mirror-image exposure on heart rate and movement of isolated heifers. Appl Anim Behav Sci 1999;63(2): 93–102.
  38. Parrott RF, Houpt KA, Misson BH. Modification of the responses of sheep to isolation stress by the use of mirror panels. Appl Anim Behav Sci 1988;19: 331–338.
  39. Jones SE, Phillips CJC. The effects of mirrors on the welfare of caged rabbits. Anim Welf 2005;14(3): 195–202.
  40. Wells DL. Sensory stimulation as environmental enrichment 494 for captive animals: a review. Appl Anim Behav Sci 2009;118(1): 1–11.
  41. Fuss J, Richter SH, Steinle J, Deubert G, Hellweg R, Gass P. Are you real? Visual simulation of social housing by mirror image stimulation in single housed mice.. Behav Brain Res 2013 Apr 15;243:191-8.
    doi: 10.1016/j.bbr.2013.01.015pubmed: 23333841google scholar: lookup
  42. Fureix C, Jego P, Henry S, Lansade L, Hausberger M. Towards an ethological animal model of depression? A study on horses.. PLoS One 2012;7(6):e39280.
    doi: 10.1371/journal.pone.0039280pmc: PMC3386251pubmed: 22761752google scholar: lookup
  43. Baragli P, Vitale V, Banti L, Sighieri C. Effect of aging on behavioural and physiological responses to a stressful stimulus in horses (Equus caballus). Behaviour 2014;151(11): 1513–1533.
  44. Momozawa Y, Kusunose R, Kikusui T, Takeuchi Y, Mori Y. Assessment of equine temperament questionnaire by comparing factor structure between two separate surveys. Appl Anim Behav Sci 2005;92(1): 77–84.
  45. Yarnell K, Hall C, Royle C, Walker SL. Domesticated horses differ in their behavioural and physiological responses to isolated and group housing.. Physiol Behav 2015 May 1;143:51-7.
    doi: 10.1016/j.physbeh.2015.02.040pubmed: 25725117google scholar: lookup
  46. Blackmore TL, Foster TM, Sumpter CE, Temple W. An investigation of colour discrimination with horses (Equus caballus).. Behav Processes 2008 Jul;78(3):387-96.
    doi: 10.1016/j.beproc.2008.02.003pubmed: 18359171google scholar: lookup
  47. Saslow CA. Factors affecting stimulus visibility for horses. Appl Anim Behav Sci 1999;61: 273–284.
  48. Seyfarth RM, Cheney DL, Bergman TJ. Primate social cognition and the origins of language.. Trends Cogn Sci 2005 Jun;9(6):264-6.
    doi: 10.1016/j.tics.2005.04.001pubmed: 15925802google scholar: lookup
  49. Poulin-Dubois D, Brooker I, Chow V. The developmental origins of naïve psychology in infancy.. Adv Child Dev Behav 2009;37:55-104.
    pubmed: 19673160doi: 10.1016/s0065-2407(09)03702-1google scholar: lookup
  50. Kondo N, Izawa E, Watanabe S. Crows cross-modally recognize group members but not non-group members.. Proc Biol Sci 2012 May 22;279(1735):1937-42.
    pmc: PMC3311902pubmed: 22217722doi: 10.1098/rspb.2011.2419google scholar: lookup
  51. Gallup GG Jr, Anderson JR, Shillito DJ. The mirror test. In: Bekoff M, Allen C, Burghardt GM editors. The cognitive animal: Empirical and theoretical perspectives on animal cognition. Cambridge MA: The MIT Press; 2002. pp. 325–333.
  52. Povinelli DJ, Rulf AB, Landau KR, Bierschwale DT. Self-recognition in chimpanzees (Pan troglodytes): distribution, ontogeny, and patterns of emergence.. J Comp Psychol 1993 Dec;107(4):347-72.
    pubmed: 8112048doi: 10.1037/0735-7036.107.4.347google scholar: lookup
  53. Gallup GG Jr, Povinelli DJ, Suarez SD, Anderson JR, Lethmate J, Menzel EW Jr. Further reflections on self-recognition in primates. Anim Behav 1995;50: 1525–1532.
  54. Lesimple C, Sankey C, Richard MA, Hausberger M. Do horses expect humans to solve their problems?. Front Psychol 2012;3:306.
    pmc: PMC3426792pubmed: 22936923doi: 10.3389/fpsyg.2012.00306google scholar: lookup
  55. Chelazzi L, Perlato A, Santandrea E, Della Libera C. Rewards teach visual selective attention.. Vision Res 2013 Jun 7;85:58-72.
    doi: 10.1016/j.visres.2012.12.005pubmed: 23262054google scholar: lookup
  56. Rogers LJ, Vallortigara G, Andrew RJ. Divided brains: the biology and behaviour of brain asymmetries. Cambridge University Press; 2013.
  57. Larose C, Richard-Yris MA, Hausberger M, Rogers LJ. Laterality of horses associated with emotionality in novel situations.. Laterality 2006 Jul;11(4):355-67.
    doi: 10.1080/13576500600624221pubmed: 16754236google scholar: lookup
  58. Basile M, Boivin S, Boutin A, Blois-Heulin C, Hausberger M, Lemasson A. Socially dependent auditory laterality in domestic horses (Equus caballus).. Anim Cogn 2009 Jul;12(4):611-9.
    doi: 10.1007/s10071-009-0220-5pubmed: 19283416google scholar: lookup
  59. Ollivier FJ, Samuelson DA, Brooks DE, Lewis PA, Kallberg ME, Komáromy AM. Comparative morphology of the tapetum lucidum (among selected species).. Vet Ophthalmol 2004 Jan-Feb;7(1):11-22.
    pubmed: 14738502doi: 10.1111/j.1463-5224.2004.00318.xgoogle scholar: lookup
  60. Soler M, Pérez-Contreras T, Peralta-Sánchez JM. Mirror-mark tests performed on jackdaws reveal potential methodological problems in the use of stickers in avian mark-test studies.. PLoS One 2014;9(1):e86193.
    doi: 10.1371/journal.pone.0086193pmc: PMC3903501pubmed: 24475085google scholar: lookup

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    doi: 10.1007/s10071-022-01696-4pubmed: 36173469google scholar: lookup
  2. Kohda M, Sogawa S, Jordan AL, Kubo N, Awata S, Satoh S, Kobayashi T, Fujita A, Bshary R. Further evidence for the capacity of mirror self-recognition in cleaner fish and the significance of ecologically relevant marks. PLoS Biol 2022 Feb;20(2):e3001529.
    doi: 10.1371/journal.pbio.3001529pubmed: 35176032google scholar: lookup
  3. Jastrzębska E, Sadowska J, Wnuk-Pawlak E, Różańska-Boczula M, Janczarek I. Exploratory Behaviours of Primitive Horses Based on Konik: A Preliminary Study. Animals (Basel) 2021 Mar 12;11(3).
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  5. Kohda M, Hotta T, Takeyama T, Awata S, Tanaka H, Asai JY, Jordan AL. If a fish can pass the mark test, what are the implications for consciousness and self-awareness testing in animals?. PLoS Biol 2019 Feb;17(2):e3000021.
    doi: 10.1371/journal.pbio.3000021pubmed: 30730878google scholar: lookup
  6. Li CY, Hofmann HA, Harris ML, Earley RL. Real or fake? Natural and artificial social stimuli elicit divergent behavioural and neural responses in mangrove rivulus, Kryptolebias marmoratus. Proc Biol Sci 2018 Nov 14;285(1891).
    doi: 10.1098/rspb.2018.1610pubmed: 30429304google scholar: lookup
  7. Manolăchescu D, Tripon M, Crecan C, Tătaru M, Papuc I. Emotional contagion in human-horse interactions: A pilot study investigating the role of stress and body language in emotional transfer. Open Vet J 2025 Nov;15(11):6050-6058.
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