Study Confirms Horses Respond to Negative Reinforcement

If we train our horses correctly, we should sense that they get “lighter” as training progresses. In other words, we should be able to execute cues with less force and get the same result. But until now, measuring that “lightness” has always just been a matter of “feeling,” so to speak: Danish researchers have put the science behind the feeling.

In order to accurately assess—and confirm—this development of lightness, Line Peerstrup Ahrendt, PhD, researcher in the department of Animal Science at Aarhus University in Tjele, used an algometer to measure the force of a cue in a basic pressure-release (negative reinforcement) training situation. Ahrendt presented her work at the 9th Conference of the International Society for Equitation Science, held July 17-19 at the University of Delaware in Newark.

Negative reinforcement relies on the use of pressure and timely release of pressure to train horses. It’s only called “negative” in a mathematical sense because something (pressure) is taken away during the training process to reward the horse for a correct behavioral response.

“Most equine training is based on negative reinforcement, but there are actually very few scientific studies which have investigated horses’ ability to learn from it,” said Ahrendt. “And learning ability is often subjectively evaluated by experienced riders. So the development of a test which could evaluate horses’ ability to learn through negative reinforcement would give us a more objective method to evaluate equine learning ability and perhaps training ability.”

In her study, Ahrendt taught 24 young Icelandic horses that had only been halter-trained to move their hips away from pressure using negative reinforcement. She applied pressure to the horses’ thighs using an algometer—a hand-held device that creates gradually increasing pressure while measuring the amount of pressure being created at any moment. She chose a device that had a pressure surface of 16 mm, which is approximately the size of a human fingertip, to replicate real training situations.

Once the horses moved away from the pressure, she removed the algometer and noted the amount of force required to get the horse to move. She repeated the experiment on the same horses over three days (10 trials the first day, seven the second day, and five the third day) to see how their training evolved.

She found—and confirmed what many horse trainers have already long suspected—that horses do learn to recognize the pressure very quickly and to act in a way that will stop the pressure as soon as possible. The study horses consistently required less pressure from the algometer to react as training progressed.

“The study horses moved quite a bit faster to the pressure every day,” Ahrendt said.

In other words, Ahrendt provided scientific proof that horses not only learn from negative reinforcement, but they do indeed become “lighter” with proper negative reinforcement training.

However, lightness does depend on using negative reinforcement correctly, Ahrendt added, and the timeliness of the pressure release is critical.

Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.