Scientists assessed the effect of pictures in reducing stress in sheep. They put sheep in an isolated pen for 15 minutes (a stressful experience in itself). Some looked at a blank wall while others looked at pictures of either a sheep’s face, a goat face or an inverted triangle (roughly the same shape and size as the animal faces). The confined sheep were less stressed when they saw pictures of other sheep — a picture of a goat wasn’t comforting and possibly even more disturbing than seeing a triangle.
In related research, sheep were given the option of two doors, both of which led to food. The doors had pictures of a smiling human or a stressed person, or a contented sheep or a stressed sheep.
"They vastly preferred to press the smiling human or the animal that has just had a meal and is feeling all right with life," said Dr. Kendrick, who conducted the research at Cambridge University, in an interview with the BBC.
Horses also seem to read emotion. When shown pictures of smiling and angry people, horses reacted strongly to the images of angry humans. Their heart rate rose and they immediately turned to look at the image with their left eyes. Apparently, the emotional impact of images is best appreciated by the left eye (which conveys messages to the right hemisphere of the brain).
Sources: Face pictures reduce behavioral, autonomic, endocrine and neural indices of stress and fear in sheep. Ana P. da Costa, Andrea E. Leigh, Mei-See Man & Keith M. Kendrick. Proceedings of the Royal Society B: Biological Sciences. 271 (1552): 2077-84. 2004; Sheep like smiles say researchers. BBC News. June 11, 2004; Functionally relevant responses to human facial expressions of emotion in the domestic horse (Equus caballus). Amy Victoria Smith, Leanne Proops, Kate Grounds, Jennifer Wathan and Karen McComb. Biology Letters. 12: 1-4. 2016
- Janet Wallace