A recent study investigated whether the human-horse bond could be considered ‘attachment’ by the scientific definition of the term. This involves security and comfort being derived from the relationship.
The relationship and attachment of dogs and cats to humans has been studied much more than that of horses, but this preliminary study with 12 horses is the starting place for more research in future.
The twelve horses were assessed before the training began in an arena with four novel objects and two unfamiliar humans. This assessed their fear responses to new situations and whether they found the presence of unfamiliar humans to be reassuring.
The horses were then trained over a period of ten days for fifteen minutes by the same trainer in ten simple tasks including stepping forward, stopping, standing still, and moving either the shoulders or the hips sideways. One group of horses was trained this using only negative reinforcement (the removal of pressure to reinforce the correct response). The other two groups were trained with combined reinforcement, which is negative reinforcement combined with positive reinforcement (the addition of something pleasant as a reward for a correct response). One combined reinforcement group had food rewards, and the other had wither scratching as a reward.
A post training test was conducted with four new novel objects and two people near the objects. One of these people was unfamiliar, and the other was the horses’ trainer so that it could be assessed if the horse showed attachment behaviours towards the familiar person. The researchers also wanted to see if the method of training used affected the horses’ responses to novel objects.
Lastly, a handling test was conducted consisting of five challenging and potentially fear inducing situations that the horse was led through by an unfamiliar handler or by the trainer to investigate effect of training method and familiarity of the human on the horses’ reactions.
The researchers were unable to find a difference between horse behaviour toward the trainer versus behaviour toward the stranger between the pre- and post-tests. Horses that were willing to investigate the novel objects in the pre- test did so also in the post-test. Their heart rates, however, were significantly lower in the post-test, indicative either of the horse getting used to the testing scenario, or perhaps showing an effect of correct training in producing relaxation, which has been demonstrated in other studies. During the handling test, there was no difference in measured behaviours when being handled by the trainer versus the stranger.
There is not enough evidence from this study to conclude that scientific attachment occurs between horses and humans, but the reasons for this may be several.
- There were few training sessions. Horses may take longer to form an attachment than other species.
- The horses were lesson horses. They were therefore frequently handled by many humans and may have generalized to consider all humans as positive.
- This was a pilot study. There were only 12 horses used, which is a good start but further research is required.
Hartmann, E; Rehn, T; Christensen, JW; Nielsen, PP; and McGreevy, P. (2021) From the Horse’s Perspective: Investigating Attachment Behaviour and the Effect of Training Method on Fear Reactions and Ease of Handling—A Pilot Study. Animals 11: 457. Open Access: https://www.mdpi.com/2076-2615/11/2/457