Oral Presentation The International Society for Anthrozoology (ISAZ): 27th Annual Conference 2018

Goats differentiate human emotional facial expressions. (#71)

Alan G McElligott 1 2 , Natalia Albuquerque 3 4 , Carine Savalli 5 , Marie-Sophie Single 6 , Christian Nawroth 1 7
  1. Biological and Experimental Psychology, Queen Mary University of London, London, United Kingdom
  2. University of Roehampton, Roehampton, United Kingdom
  3. Department of Experimental Psychology, Institute of Psychology, São Paulo, Brazil
  4. School of Life Sciences, University of Lincoln, Lincoln, United Kingdom
  5. Department of Public Policies and Collective Health, Federal University of Sao Paulo, Santos, Sao Paulo, Brazil
  6. Physiology Weihenstephan, Technical University of Munich, Munich, Bavaria, Germany
  7. Institute of Behavioural Physiology, Leibniz Institute for Farm Animal Biology, Dummerstorf, Germany

Introduction: A key function of human facial expression is to communicate emotional states. Recently it has been shown that dogs and horses (two species domesticated for working closely with people) are capable of perceiving human emotional states via their faces. However, it is not known whether other animals, particularly those domesticated primarily for production such as goats, are able to perceive human emotional cues. We investigated whether goats are capable of discriminating human faces showing different emotions.

Methodology: In the training phase, 20 goats were rewarded with food for approaching the experimental area, by a researcher with a neutral expression. In the tests, two images of an unfamiliar human face with either a happy or angry face were presented simultaneously for 30s, on the left and right sides of the experimental area. Each subject received four repetitions, counterbalanced for side of stimuli presentation (left vs right) and human gender (woman vs man).

Main Results:  Goats were more likely to first approach happy faces (Χ2 = 6.66, p = 0.009), but did not interact more often or for longer with those images (Χ2 = 1.46, p = 0.226, Χ2 = 3.73, p = 0.053, respectively). We also found that goats first approached, interacted more often, and for longer, with happy faces when they were positioned on the right side (first choice: Χ2 = 8.90; p = 0.002; rate: Χ2 = 8.01; p = 0.004; duration: Χ2 = 8.24; p = 0.004). However, no such preference was found when happy faces were presented on the left. Face gender and goat sex had no effect on the preference.

Principal Conclusions and Implications for Field: Goats can discriminate human facial expressions with different emotional valences and prefer to interact with happy faces. In addition, perceptual lateralization plays a role in the processing of positive human emotional information. These findings suggest that the ability of animals to perceive human emotional facial cues is not limited to those with a long history of domestication as companions, and therefore may be far more widespread than previously believed.