Horses' preferential looking to humans based on problem-solving ability

Abstract

The ability to recognize and evaluate others is considered to be an important ability in selecting cooperative partners. There have been some studies on this ability in both humans and nonhuman animals, however, little empirical research has been conducted to examine how horses perceive humans. Here, we investigated whether horses can evaluate the problem-solving ability of humans in an unsolvable task. We showed horses a pair of two experimenters, one who can open the lid of a container (problem solver) and the other who cannot open the lid of the container (problem nonsolver), trying to open the lid of the container either with or without food in it. Gaze duration toward each experimenter was recorded and used as a proxy measurement of the attention of the horses. Horses watched the problem solver longer than the problem nonsolver in the food condition. They also watched the problem solver for longer in the food condition compared to the no food condition. These results suggest that horses can recognize the problem-solving ability of humans.