Just how special is the human-horse bond? Researchers investigate

Riders generally consider bonding with their equine companions to be a crucial part of their relationship, but how do horses view such relationships?

Researchers in Sweden delved into the nature of the human-horse relationship in a study reported this week in the journal Applied Animal Behaviour Science.Linköping University researcher Paulina Lundberg and her colleagues wanted to know whether training style affected the nature of the relationship

They also monitored the reaction of horses in a separation-reunion experiment involving their owners and a stranger.

Lundberg, joined in the study by Lina Roth, also with Linköping University, and Elke Hartmann, with the Swedish University of Agricultural Science, noted that humans have shared a long history with horses, which today are mainly considered companions for sports and leisure activities.

“Many riders and horse owners would consider their horse as part of the family and would relate to it as they would to a child or to another family member,” they said“They may also refer to the relationship as one marked by mutual trust, respect and affection.”“Many riders and horse owners would consider their horse as part of the family and would relate to it as they would to a child or to another family member.” They noted that the human perspective on the human-horse relationship has been investigated, but there has been little focus on the horse’s perspective.

The trio set out to determine whether horses show attachment-related behaviours towards humans that fulfil the four features of attachment.

These are:

  • Proximity seeking (preferring to be near the human);

  • Safe haven (relief from stress due to the comfort and support provided by the person);

  • Secure base (increased exploration due to feeling safe); and

  • Separation distress (feeling distressed in the absence of the attachment figure).

The question of whether such an attachment exists has important implications, they suggest.

“For example, clarity in this domain will assist in demystifying the concepts of trust and respect and moderate inappropriate human expectations in training contexts.

“Alternatively, trust in humans based on an attachment bond could help to reduce a horse’s arousal in a frightening situation.”

For their study, the researchers recruited 26 privately owned horses — 14 mares and 12 geldings — for an experiment in an indoor arena measuring 20m by 14m. Most of the horses were familiar with the arena.

The owners, all of whom had owned their horses for at least a year, were also asked questions about their training methods, allowing the researchers to categorise the horses depending on whether they used mainly negative reinforcement, positive reinforcement, or a combination of both during training.

They also completed a horse personality questionnaire.

The separation-reunion experiment involved a protocol in which the owner walked the horse on a lead rope around the arena for three minutes. They then walked to a spot in the middle of the arena and stood there for a minute with the horse on a loose lead rope. The owner then left the arena and was out of sight from the horse for two minutes, before returning for the reunion phase.

Following a 15-minute break away from the arena, the same protocol was repeated with a person who was a stranger to the horse.

The behaviour of the horses was monitored throughout the experiment.

The results showed that the horses spent more time near the arena door when separated from both the owner and the stranger when compared to the reunion phase. They also sought human proximity during reunion, both with the owner and stranger.

The horses’ heart rates were higher during the separation compared to the reunion with both the owner and the stranger, suggesting that the horses were distressed when left alone.

These results, they said, are examples of attachment-related features and suggest that horses consider both the owner and the stranger as a safe haven.

“However, the results are not clear as to whether or not horses perceive their owners as a secure base since their exploratory behaviour during owner reunion was similar to that during stranger reunion.

Interestingly, they said, the horses trained with positive reinforcement spent the most time near the door during separation from the stranger. There was a similar tendency during owner separation.

These horses also spent more time close to the stranger and had more physical contact with the stranger than horses in the other two training-style groups.

The researchers said the study revealed some attachment-related behaviours of horses towards humans, even though the results cannot resolve whether these fulfil all criteria for an attachment-bond.

Interestingly, horses showed stress-relieved behaviours and decreased heart rate in the presence of both the owner and stranger, suggesting a safe-haven effect irrespective of familiarity of the human.

Discussing their findings, the authors said the horses had shown at least two features of attachment, namely separation-related distress and safe heaven as reflected in heart rates.

They said future studies should address the daily time owners spend with their horses and include information about training methods used, the owner attachment style, and how much contact horses have with companions, given the importance of touch both during horse training and with other horses.