Basic Horse Temperament and Behavior (Book Excerpt)

Those who have worked with different breeds of horses almost always have their opinion as to basic temperament and behavioral characteristics of certain breeds. Few would not agree that in general the warmblooded breeds, such as Thoroughbreds and Arabians, are generally more reactive than the more stoic, cold-blooded (draft) or pony breeds. Also, horse breeders have long recognized the heritability of certain basic temperaments in lines of horses and select for those characteristics when breeding. So there is no doubt that genetics plays a big role in basic temperament and behavioral characteristics of horses. While many good behavioral characteristics and problem behavioral characteristics are heritable, they are probably not highly heritable. For example, a stallion with a tendency to savage people is probably more likely to have some male offspring born with that tendency than a stallion which does not savage people. But the savage stallion is also likely to have many male offspring which do not have the tendency. The same is true of the tendency for positive traits; there are no guarantees.


Probably the broadest generalizations concerning basic equine temperament and behavior involve comparisons of mares, stallions, and geldings. Stallions, of course, are intact males. The majority of equestrians would not consider keeping or using a stallion for other than breeding. A stallion is typically very strong physically, and strong willed. If not trained when and where to breed, a stallion will instinctively respond sexually whenever the occasion arises. In most equine athletic disciplines, those who prefer to work with stallions usually appreciate the strength and competitive drive of an intact male horse. For such experienced handlers or trainers, the sexual and aggressive behavior of a stallion is remarkably well controlled with simple behavior modification. The key to success with stallions appears to be firm, consistent, judicious, and skillful training. While physical size and strength can help, it is certainly not necessary for handling and training stallions. In fact, trying to control a stallion with brute strength alone is usually futile.

A rowdy performing stallion actually might benefit from the opportunity to breed. Providing clear signals that distinguish breeding time and performing time can help most stallions learn and abide by the difference. In other words, for some stallions, it appears easier for them to suppress their sexual behavior if they actually have a time and place where it is allowed and encouraged.

Normal stallion behavior also poses housing and general management challenges. Stallions are usually pastured, housed, and transported separately from other horses. Beyond the obvious reasons of preventing sexual interaction and breeding, this is done to avoid wear and tear on the stallion as he will try to whatever extent possible to perform normal harem stallion behavior. This includes pacing fence lines and stalls, and trying to fight off other males.

Mares and geldings are more popular choices for performance horses in general than stallions. Geldings tend to be less aggressive, perhaps less distracted by other horses, and easier to house and transport than stallions. However, castration, regardless of the age or previous sexual experience, does not always eliminate all stallion-like behavior. If given the opportunity, as many as half of geldings will show stallion-like behavior to mares, many will herd mares, and even mount and appear to breed. Similarly, while castration does tend to "mellow" most horses, it does not eliminate general misbehavior. Traditional behavior modification is usually much more effective in controlling sexual and aggressive behavior in a gelding under saddle or in-hand than it is with an intact stallion. For example, in most cases it is easier to eliminate biting behavior in a gelding than in an intact stallion. Also, treatment aimed at quieting sexual and aggressive behavior, such as progesterone, is typically more effective in geldings than in intact stallions. This stands to reason, because the actual male hormones from the testicle that increase the sexual and aggressive motivation in a stallion are not present in the gelding.

Mares, like geldings, are generally more docile than stallions. The one common complaint about mare temperament and behavior is specific problems and inconsistencies in performance related to their estrus cycle.

With gender, like many factors that seem to affect equine temperament and behavior, there certainly is an interactive effect of people. People who like and appreciate stallions, for example, seem to really bring out the best in a stallion. They seem to develop a mutual respect. The same is true for those who like to work with mares. There are some people who always ride mares and never seem to complain of estrus cycle-related performance problems.


Age of a horse is almost always confounded with experience and training, so it is difficult to evaluate effects of age on basic temperament. However, there are some generalizations that can be made. Most young horses are more curious, playful, and reactive than mature horses. Scientific studies indicate that younger horses learn more readily than mature horses. They likely adapt more readily to changes in physical and social environment as well. Most very old horses are more "sensible," quiet, and even more docile than young or middle-aged horses. Of course, this impression might simply be the result that only nice horses are kept into old age.

Handling and Environment

In the whole scheme of things, the critical factors in most aspects of domestic horse temperament and behavior are their management, environment, and particularly their interaction with people. People with lots of horse behavior problems don't like to hear this, and most people with lots of behavior-problem-free horses know this very well. The personality of most horses remains somewhat plastic throughout life, and it is greatly affected by the animals and people around it. Probably horses are most affected by their first handling experiences when young, but even aged horses can be affected by how they are handled. It is not at all uncommon for sequential owners or trainers of a particular horse to describe it quite differently. Even within the same time period, a horse can show very different attributes depending on the people or environment around it. Honest trainers often admit personality or environmental conflicts, and recognize that a particular horse might do better with another trainer or in a more quiet or more active stable.

About the Author

Sue McDonnell, PhD, Certified AAB

Sue M. McDonnell, PhD, is a certified applied animal behaviorist and the founding head of the equine behavior program at the University of Pennsylvania's School of Veterinary Medicine. She is also the author of numerous books and articles about horse behavior and management.

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