A ubiquitous term at the salon or barbershop is “cowlick.” That pesky wave of hair that just won’t lay flat is sometimes more pronounced in some than others. But everyone has a hair whorl at the crown of his or her head. Cattle and other livestock such as horses have a similar cowlick whorl but in a more obvious place—usually right between the eyes. And it turns out these whorls may be more than an aesthetic quirk.
A little over two decades ago, animal behaviorists began to notice a connection between crazy hair whorls and crazy animals. Turns out there is science behind hair whorls and brain development—both in bovines and humans.
Dr. Temple Grandin, professor of animal science at Colorado State University and author of the best-selling book Animals in Translation, first noticed a connection between the location of a bull’s hair whorl and whether the animal was excitable when handled by humans.
Studies showed that location—meaning above, between or below the eyes—as well as shape of the whorl could be, to some extent, a predictor of excitable behavior in cattle.
In 1995, Grandin published findings that cattle with whorls high on the face—above the eyes—were significantly more excitable than animals with whorls lower on the face. This could be utilized by farmers for breeding decisions, helping them choose animals with calmer temperaments for their breeding programs.
But how, then, are hair growth patterns and temperament related? It all has to do with brain development. Skin cells and neurons (brain cells) come from the same location in the embryo, a layer of cells called the ectoderm. As these cells migrate during embryonic development, both brain cells and skin cells remain intertwined, especially on the head.
A study from the University of Limerick in Ireland in 2008 demonstrated that horses with clockwise hair whorls were significantly more likely to move toward the right, or begin a gait with the right-sided hooves. In essence, these horses were right-handed.
And the horses with counterclockwise whorls? Yep, lefties. Research has also shown that within the human population, the majority is right-handed and demonstrates a clockwise hair whorl.
Apart from a whorl’s directionality and location, Grandin has also found that cattle with very odd-sized or -shaped whorls are associated with abnormal and sometimes dangerous behavior. Normal hair whorls between the eyes of a cow are typically circular and either turn clockwise or counter-clockwise. Abnormal whorls would be those that appear either very high or very low on the forehead or are more linear in shape.
She warns against cattle with a stripe down their face akin to a lightning bolt. Although rare, those animals tend to be extremely excitable and dangerous to handle.
In the early 2000s, Grandin found another interesting link with hair whorls, this time connecting the shape of the whorl with bull reproductive parameters. This time, Grandin demonstrated that bulls with round whorls had a higher percentage of normal sperm as compared to bulls with an elongated whorl on their faces. Bulls with round whorls averaged 77.6 percent normal sperm while bulls with elongated whorls had 69.4 percent normal sperm.
While a 77 to 69 percent difference may not seem like much, remember that for a bull to pass a breeding soundness exam (BSE), he should have a minimum of 70 percent normal sperm. An abnormal whorl could mean the difference between a bull that makes the cut for entry into a breeding program and one that doesn’t.
As with the connection between whorls, temperament and embryonic development, there is also a link between skin and gonad development in the fetus.
Next time you’re among cattle, take a close look at a face and try to find the shape and location of the cowlick. You just might make some interesting connections between their hair and their personality.