Horse Behaviorist UT

09/05/2026

As I learned about individual differences in horses with different hair whorls, patterns emerged, and similarities in behavior between horses with similar hair whorls became clear. Horses with high whorls indicated a flighty temperament, and those with low whorls were mostly calm. Whorls between the eyes predicted a steady, even-tempered horse.
These patterns were fairly stable and allowed me to predict behavior with a high degree of accuracy, except for the double-whorl horse (I'm referring to side-by-side whorls, like the photo, not vertically placed whorls). I found horses with those types of hair whorls presented a paradox that didn't make sense. They were sometimes exceptional horses- friendly, smart, easy to train or ride, and many I encountered were champion reining horses, racehorses, or show horses.
Or they were a pain in the ass. Horses that would kick, bite, buck, refuse to load in a trailer, refuse to enter a starting gate, or stop at jumps, and in some cases, were downright dangerous. As a farrier, I found they were smart trouble-makers and would wait until my guard was down before letting me have it.

In one sense, they were predictably unpredictable. Wanting to know more, I began to ask myself: are double-whorls random, or are they inherited? I had already figured out the inheritance of single whorls (recently confirmed in a large published journal article), but I had no idea about the double whorls. But before long, I figured it out.

One day I was trimming the feet of a woman’s mare, and standing at the fence were two of the mare's offspring. One was a three-year-old gelding and the other a yearling filly. Both had double hair whorls, side by side, and high.

When I stepped back and looked at the mare, she had a single whorl, high and on the right. After I finished the trim, I asked the woman who sired the two offspring and she told me her neighbor down the road owned the sire, gave me his name, and directions to his farm. Afterward, I drove down to take a look, and lo and behold, the sire had a single whorl high and on the left. I thought, “Wow, that's pretty simple.” Breeding a lefty to a righty, and you get the doubles.

I was eager to find more examples of this inheritance pattern, but it was not easy. For most of the horses I encountered with doubles, the owners didn't know either the sire or the dam. But eventually, I found enough to convince myself that the inheritance pattern was real, and by always asking questions, something else emerged that blew my mind.

One day I was talking to the owner of a double whorl mare, and I mentioned the inheritance pattern I'd uncovered when suddenly he stepped back and said, “My mother is right-handed, and my dad is left, and I have double whorls on my head.” I had to see for myself, so I asked him to turn around.

Like I said before, it blew my mind !

This discovery happened about 35 years ago, and I've since confirmed it countless times in three species. Look at the similarities between a human child, a horse, and a Holstein cow. The doubles in the picture all show whorls that rotate left and right. This pattern can't be random.

Next time, I'll tell you what I think it means and how it explains the double-whorl animal's paradoxical behavior.

09/05/2026

09/03/2026

It’s been some time since I’ve posted any thoughts on horse hair whorls. As I sat down to share some of the current scientific research, I found so much that it was hard to know where to start. Instead, I decided to share where I find this research and let you search and read it for yourself.
Some of you will know this and others might be surprised to learn that there is a Google separate from the one we all know and use every day. It’s called Google Scholar, and you can find it by going to regular Google and typing in the keywords Google Scholar. Scholar publishes mostly peer-reviewed scientific journal articles. When the page opens, you’ll find a keyword bar. Type in the keywords I use, “horses, cattle, hair whorls, genetics, behavior” all together. Once you type in the keywords, a list comes up of the most popular articles. At the top right of the page you can choose the year. I always choose the most current year and look back from there. Good reading!

In my next post, I’ll share some really interesting information on double whorls.

11/06/2023

http://horsebehavioristutah.com/hair-whorl-position-and-laterality-side-preference-defined/

11/06/2023

http://horsebehavioristutah.com/research-origins/

10/09/2023

Hair whorls predict left or right pawed dogs. Left pawed dogs make the best seeing eye dogs.

Several studies have assessed different components of lateralization. To date, the relationships between the 3 measures of laterality, structural, mot…

10/09/2023

When a dogs tail is docked, it's like cutting off his tongue so he can't talk.

Left-right asymmetries in behavior associated with asymmetries in the brain are widespread in the animal kingdom [1], and the hypothesis has been put forward that they may be linked to animals’ social behavior [2, 3]. Dogs show asymmetric tail-wagging responses to different emotive stimuli [4]—t...

09/15/2023

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𝐇𝐀𝐈𝐑 𝐖𝐇𝐎𝐑𝐋 𝐏𝐎𝐒𝐈𝐓𝐈𝐎𝐍 𝐀𝐍𝐃 𝐋𝐀𝐓𝐄𝐑𝐀𝐋𝐈𝐓𝐘 (𝐬𝐢𝐝𝐞 𝐩𝐫𝐞𝐟𝐞𝐫𝐞𝐧𝐜𝐞) 𝐃𝐄𝐅𝐈𝐍𝐄𝐃

This knowledge is a game changer in the horse training business and for those in all the competition sports, and a valuable guide for horse owners looking to find the perfect horse for their lifestyle and riding pleasure. Geneticists in three countries have provided the first scientific evidence of the inheritance of hair whorls, links to behavior, and specific genes linked to certain hair whorl patterns. There's no scientific evidence more definitive than genetic evidence. Dr. Temple Grandin and I at Colorado State University waited 28 eight years since we published the first scientific evidence of the link from hair whorls to behavior for the genetic evidence we always knew would come. We never claimed to discover the relationship between hair whorls and behavior; people worldwide for thousands of years have casually observed the relationship. What we did that was new was show the link to lateralization of the nervous system and the hair whorls association with functional specialization of the cerebral hemispheres of the brain. I studied and documented the relationship for ten years before meeting Temple Grandin, working as a farrier and horse trainer. I learned the practical application of this knowledge in real-world situations before seeking and finding the academic support needed to make this useful information available to everyone.

This post aims to clarify and unify common terminology and principles of hair whorl height and position, either left, right, or center. For future posting on this page, this information is essential for you. The most important language to clarify relates to the side preference exhibited by horses and its relation to horse welfare concerns. The terminology in the horse industry, as is in the scientific language, is broad and varies between people in the US and other countries. The formal scientific term for this phenomenon is lateralization of the nervous system. Some scientists use a less formal term, 𝒍𝒂𝒕𝒆𝒓𝒂𝒍𝒊𝒕𝒚. 𝑯𝒂𝒏𝒅𝒆𝒅𝒏𝒆𝒔𝒔 is the general term used to describe the phenomenon across species that includes human handedness, paw preference in dogs, footedness in birds, and side preference in cattle, horses, and other herbivores. In my writing, I interchange the terms laterality, handedness, and side preference depending on sentence context, but they all mean the same thing.

I drew this graph on this horse because this horse represents a large proportion of horses and the hair whorl type that suffers from the most severe welfare concerns. It has a single whorl, is left of center, and is very.

𝐇𝐀𝐈𝐑 𝐖𝐇𝐎𝐑𝐋 𝐇𝐄𝐈𝐆𝐇𝐓

"Very Low" defines a non-reactive horse with low fear. "Low" whorls represent a horse as slightly more reactive than the "very low." "Very Lows" and "Lows" show minimal side preferences, and the hair whorls are usually in the center of the midline. The V-lines on the graph represent how, as the whorl gets higher, the side preference increases.

𝐌𝐈𝐃𝐃𝐋𝐄 𝐚𝐧𝐝 𝐇𝐈𝐆𝐇

Most horses are in the Middle and High Range. The reactivity and fearfulness are in the mid-range, with some variation. Reactivity is higher in the top portion of the High range and lower reactivity in the lower middle range. The V-shape on the graph represents side preferences. The higher the whorl on the forehead, the stronger their side preference.

𝐇𝐈𝐆𝐇 𝐀𝐍𝐃 𝐕𝐄𝐑𝐘 𝐇𝐈𝐆𝐇

A smaller portion of horses are in the "High" and "Very" High range. Both high and very high define highly reactive and fearful horses. Side preference is highest in these two ranges, and the distance left or right from the midline also increases the side preference strength. This horse represents very high nervous system reactivity and laterality but not extreme laterality (side preference). A hair whorl closer to V-line would be an example of extreme laterality.

𝐇𝐀𝐈𝐑 𝐖𝐇𝐎𝐑𝐋 𝐄𝐏𝐈𝐂𝐄𝐍𝐓𝐄𝐑

The epicenter defines the position of the whorl. This horse has a very high whorl slightly off to the horse's left side. This horse is highly reactive. The side preference is strong but not the strongest., and its natural fearfulness is very strong.

𝐒𝐔𝐌𝐌𝐀𝐑𝐘

Approximately 70% of horses have a left side whorl in the medium to high ranges. 10% to 15% have hair whorls on the right side. Approximately 10% have two side-by-side whorls, always in mid-to-high ranges, never low. The double side-by-side whorls we considered normal in our research.The doubles, either side by side or one above the other, are harder to define and require a separate post to clarify.

The remaining 5% have multiple or two whorls, one above the other. In our research, we considered these types of whorls abnormal.

The horse in this picture will favor the right lead and travel better in a circle to the right or clockwise. The left whorl and right turning preferences are similar to most right-handed people. The right side whorl is opposite, like left-handed people. The horse with a high right side whorl favors the left lead.

This horse's left eye is the "look out for danger" eye in horse's with a left side whorl, and prefers the right lead. The side of the whorl is the side the horse will give a farrier the hardest time. The opposite holds for the horse with a right side whorl.This horse's right eye is the "look out for danger" eye in horse's with a right side whorl, and this horse prefers the left lead.

The high reactivity(fearfulness) and the laterality (side preference) of the horse in the photograph and a horse with the opposite on the right side are the types of horses I encountered most while working as a farrier and horse trainer. The horses with the high right and left hair whorls show the most potential as high-performance horses, but they also represent the horses with the most severe welfare concerns. Unfortunately, when they have behavior problems, they are the most dangerous and unpredictable. It all depends on how they are raised and handled. Any clarifying questions are welcome.