Horses can smell human emotions – Cross species communication of emotions between humans and horses. Do we have to learn a lesson?

What we know from practice
Celina Skogan

Have you made that observation?
The same horse, that is reacting totally scared with one person, is perfectly calm with another one. Apparently unexplainable.

During lessons, students often hear me commenting on their breath and their attitude regarding their horses and the horses’ state of relaxation – with immediate influence on the horse. Experience has shown that attitude and intention have a fundamental influence on the quality of the time spend together and, of course, training. The aware spectator and instructor often observes the human reacting with tension long before the horse shows any signs of nervousness.

Just recently, I met a very interesting case during a clinic. The student was meeting  me and the academic art of riding for the first time. During the theory session already, she described her difficult and often dangerous horse and was pleading for help. In the arena, the horse was running like crazy on a long line and started to attack the owner. In order to get a picture of the situation, I offered help and took the line myself, prepared for a discussion. What happened then, was exactly ….. nothing. The horse lowered the head into the sand, took a deep breath, stood perfectly still and allowed me to touch it all over its body. The audience was surprised. Me, too.  This experience taught me, how surprisingly intense horses can react to a human and how much that matters within a human-horse relationship. There is a special connection in between some horses and their humans. If we listen well, we can hear the lesson the horse is trying to teach us.

What are the fundaments for this special, emotional connection between horses and humans? Recent research has at least investigated some aspects of emotional transfer between humans and horses, and there is still much to learn…

Scientific facts
Frauke Musial

Most of us who ride and handle horses have probably at one or the other point in time experienced, that our emotional state will influence whatever we do with our four legged companions. Whether it is riding, groundwork, or simply our interactions with our furry friends while we groom or feed them. Why is this so?

Over the last couple of years, ample scientific evidence has accumulated that pet dogs can read our emotions and that they are able to evoke a picture or reflection of what humans feel. Call that a biological necessity for survival in a more or less symbiotic relationship, or call it empathy. How these findings are interpreted will to a large extend depend on how we see the world we live in. Nonetheless, the fact that our pet dogs seem to have a clue about how we feel will not come as a surprise for anybody who has or has had a pet dog. 

But how about horses? After thousands of years where horses have been used by humans because there was a need for transport, “machinery” on farms, or the utilization of horses as warfare, times have changed for the human – horse relationship, because horses are, at least in the more developed countries, no longer needed as “machinery”.  Nonetheless, to date horses are, besides still being objects of sports activities, for many people pet animals, kept without any obvious benefit. Quite the opposite, it is expensive to keep horses as pets….

Thus, there seems to be an underlying bond between humans and horses, just like the bond between pet dogs and humans that possibly has evolved through thousands of years of common history and cohabitation. Consequently, there has been a growing interest in the behavioral science of horses, including human – horse interspecies communication. Todays’ blog focusses on two scientific publications elaborating on the transfer of emotions from humans to horses.

In the first study Linda Keeling, Liv Jonare, and Lovisa Lanneborn (2009) investigated the effect of a nervous human on the heart rate of horses these humans were interacting with. Heart rate is an easy to measure indicator for arousal and stress. Heart rate increases as part of the fight-flight response and has been studied extensively in humans and other species. In their experimental setup, the participating horses were led or ridden 4 times over a distance of 30 m. The humans were told, that a co-investigator standing at the end of the distance would flash an umbrella in the fourth round. Nonetheless, the umbrella was never opened, any reaction in the fourth trial would be to the expectation of the human that an umbrella would be opened.

The heart rate of humans and horses decreased throughout the first three rounds, showing habituation to the situation over time, and then increased throughout the fourth round. The effect was particularly pronounced in the part of the experiment, where the horses were ridden and thus had direct physical contact with the human. The heart rate increase was in part accompanied by behavioral changes of the rider, such as e.g. using shorter reigns.

This study shows, that the humans reacted towards the expectation that something unforeseen could happen in round four with a slight stress response. This response was then transferred to the horse, most likely leading to a higher stress or preparedness level in the horse as well (note that the horses could not have any anticipation that something unforeseen could happen in trial four). One explanation for this transfer of the human stress response to the horses could be the behavioral changes on the human side.

Nonetheless, another more recent study by Antonio Lanata and co-workers (2018) suggests an additional possible pathway for emotion transfer between humans and horses. They also investigated changes and reactions in the horses’ heart rate as an indicator of the activity of the autonomous nervous system and thus emotional responses. However, this time in response to human odors of fear vs. happiness derived from human sweat samples in comparison to a neutral odor. The horses reacted differently to the two opposite emotions associated human odors indicating, that they were able to perceive human emotions through human sweat associated odors. The authors conclude “…that human chemo-signals affect the physiological status of horses as seen by the changes in their autonomic activity”.

Odors are, in opposition to visual and acoustic information, at least in humans, processed “subconsciously”.  The olfactory (smell) system reaches the older parts of the brain where emotions and especially fear and stress are processed, directly and unfiltered. At the same time horses are able to pick up human fear immediately through fear odors. These results replicate findings from pet dogs, which also reacted differentially to human emotional states and who seem to be able to read and respond to human emotions.

However, a word of caution while interpreting these scientific findings: How the fact, that dogs and horses are able to pick up our emotional state influences their behavior, is not easy to predict. It will depend on their relationship to humans, their “personality”, previous experience, and the actual situation. The understanding that our pets simply “mirror” us, is a rather anthropocentric perspective and ignores their true nature and capacities. (see also Callie King’s blog from Friday, the 20. September )

Nonetheless, these scientific results about the non-verbal communication of stress and fear, as well as happiness, tells a fascinating story of cross-species communication between humans and horses. This mutual line of communication is most likely born out of a common history of thousands of years. What are the consequences for us humans? We cannot lie to our horses! They know, when we are happy, when we are unhappy, when we are afraid, and, most likely also, whether we like and accept them or not. Thus, if we cannot lie to our horses, we might as well be honest to ourselves, about our fears and desires, our worries as well as our hidden agendas. Yet at the same time, our horses will know and understand, if we handle and encounter them with honesty, respect, and understanding, and whether we show compassion for their true nature and their needs. The invisible bond of communication between humans and horses provides an ancient and fundamental platform on which trust and, if you will, love can grow between us humans, and our equine companions. And maybe it is exactly that, why we still love horses even though there are not exactly “needed” any more in our modern world: they cannot pretend, they don’t lie, they are truly honest. Horses give what many of us value high, namely honesty, truthfulness, and appreciation of who we are.


Keeling LJ, Jonare L, Lanneborn L. Investigating horse-human interactions: the effect of a nervous human. Vet J. 2009 Jul;181(1):70-1. doi:v10.1016/j.tvjl.2009.03.013. Epub 2009 Apr 25. PubMed PMID: 19394879.

Lanata A, Nardelli M, Valenza G, Baragli P, DrAniello B, Alterisio A,Scandurra A, Semin GR, Scilingo EP. A Case for the Interspecies Transfer of Emotions: A Preliminary Investigation on How Humans Odors Modify Reactions of the Autonomic Nervous System in Horses. Conf Proc IEEE Eng Med Biol Soc. 2018 Jul;2018:522-525. doi: 10.1109/EMBC.2018.8512327. PubMed PMID: 30440449.

The lesson we have to learn from this
Celina Skogan

It is well established for human communication that more than 70% of all communication is non-verbal. Words and their content are just the tip of the iceberg. The message though is transferred somewhere in between the lines. (Read as well my blog about “Mindset”.)
When horses react on heart rate and scent, they may be pretty close to “reading our mind”. If they can distinguish between happiness and fear, I expect they are likely able to detect other emotions, as well. If they can read one chemical code, why not the other? (Though there is no scientific study base that we know about, yet.)

Considering that, not only the relevance for daily training is immense. Reflect as well on concepts as leadership, horsemanship, dominant training strategies. Do they still make sense?
Why is it, that a horse is walking into a trailer without a problem with one human, but not with another, why it is easily led by one person and difficult to handle by another?

Consider the situation of buying a horse. A horse that was easy to ride and handle with its former owner suddenly becomes a wild beast in its new environment and with a new rider. We listen to these stories regularly. Maybe the horse was not always drugged by the seller if things turn out wrong. By nature, a horse is a flight animal and that does not necessarily make it suitable for riding. A horse who perceives the tension of the rider on its back and can smell the fear will receive the message that there is probably a good reason to be scared.

Nonetheless, I do not believe in the concept that horses merely mirror our human emotions. Each horse is unique and has a certain character, bio and experience. Just the same as humans. Thus, the response to an individual human is as different as in between different humans. Most likely, you will like some and others you won’t. But I do believe that human intention has a profound influence on the horse and its communication. Each trainer who has worked with different horses knows how much the approach needs to change from training partner to training partner. Some horses need more engery, some horses need very little. Some like to be rewarded, others reward you.

Thinking a step further: If horses can smell and pick up on our emotions – can we make this a two way road instead of a one way street? Does that mean as well that our emotions and the way we feel can influence things for the better? Within this picture, being able to control your mindset and emotions may create a whole new setting. 

Enjoy the journey with your horse!