Number and frequency of each behavioral class observed during the warm-up and intervention steps of a standardized exercise test on a treadmill, wherein only the projector light was turned on (warm-up) and video images of another horse trotting in front of them (Intervention, Visual) or only a racetrack picture (Intervention, Control) were projected to assess social facilitation of trotting in horses.

P-value returns the probability under the null hypothesis that there was no association between the behavioral class and the group (intervention).