In the first study of its kind, researchers at the University of Guelph and the University of Sydney discovered that the skull shape and morphology of horses and donkeys may indicate the temperaments of different horse breeds.

“An unexpected discovery came up pertaining to the placement of [hair] whorls,” says Dr. Katrina Merkies, associate professor and researcher at the University of Guelph, The whorl is the point on an equine’s head where hair grows in the opposite direction from the rest, or spirals out from the center. The study revealed that whorl placement in horses almost always corresponded with the location of the olfactory bulbs, which are not only important in processing smell, but also tied to the amygdala where the brain processes learning and memory. This discovery gives some credence to anecdotal beliefs among breeders that whorl placement can indicate the temperament of a specific horse; according to folklore, a whorl located above the eye line indicates a more high-strung horse while one located below the eye line indicates a calmer animal.

These new discoveries will lead researchers to investigate the relationship between behavior and breed-specific skull morphology on a deeper level, leading to a better understanding of the behavioral differences between horse breeds.