The effects of a choice test between food rewards and human interaction in a herd of domestic horses of varying breeds and experiences

•Food is known reward whereas the reward value of human touch is unknown.•All horses demonstrated preference for treats over human interaction regardless of history.•Preference remained consistent for responses to familiar versus unfamiliar humans.•All horses exhibited increased arousal behaviors during study sessions.•Novel food causes arousal, but touch may be better for low-arousal social bonding. Humans use food rewards as positive reinforcement for training horses, but there is little evidence to show that human interaction (scratching or patting) has reward value or if domestic horses perceive human touch as social bonding. Most equine training is based on negative reinforcement, but food is a known reward for training through positive reinforcement. This study looked at how horses perceive human interaction as a form of positive reward by examining whether scratching and patting can serve as a reward for a behavior and how this compares to known rewards (treats) based on horses’ ability to use symbols to show preferences. A secondary purpose of this study was to explore behaviors before, during, and after the choice test and code changes based on known equine ethology and determine any correlations between known individual histories of horses, their behavior, and any differences in preferences for human interactions based on whether the human was familiar versus unfamiliar. For the quantitative component, the study counted the number of times each horse touched each target (touch counts) and behaviors were recorded with use of a GoPro Hero camera. The touch counts for each symbol for the last trial were compared using Observation Oriented Modelling (OOM), a non-parametric approach to analyze patterns in data, and the behaviors were coded and compared to known behaviors in equine ethology. Post-hoc analysis of final touch counts resulted in a pattern of fewer than 2 touches for both scratches and pats for most horses and consistently ten touches (the maximum) for treats for all horses. Post-hoc pattern analysis resulted in a Percent Correct Classification (PCC) index of 93.94 (c-value