How Big Is A Horse’s Brain?

Have you ever wondered how big is a horse’s brain? Anyone who has stood next to a horse will appreciate how huge their heads are! But do they have a brain to equal this?

Maybe you think that horses have huge brains, with an intelligence to match. Or perhaps in your experience horses do silly and stupid things, so they must have a tiny brain? Let’s take a look at horse brain size and find out!

What Is A Brain?

It might sound like an obvious question, but if we’re talking about the size of the brain we need to know exactly what the brain is! The brain is basically the control center of the body. In mammals such as humans and horses the brain is normally located in the head and is protected by a thick skull.

Part of the central nervous system, the brain controls thought, memory, emotion, touch, motor skills, vision, breathing, temperature, and hunger. We might just think of our brains as to where our thoughts are processed, but it controls every process that regulates our body!

What Is A Brain

The structure of the brain does not contain any muscle and is made up of a large proportion of fat and water. The remainder consists of nerve cells, blood vessels, and other cells which help to maintain healthy brain tissue.

How Big Is A Horse’s Brain?

The size of a horse’s skull is quite large, and it would be easy to assume that they have quite a big brain in there. However, the brain of a horse is quite small – about 10 to 15 centimeters (4 to 6 inches) in diameter. To put this in context, about the size of a grapefruit!

The brain of a horse weighs between 1½ pounds and 2 pounds. This is about 0.1% of the horse’s overall body weight. It is incredible to think that something so tiny is so vital in carrying out all the daily functions that allow a horse to exist!

What Affects The Size Of Horse Brain?

There is not much data available to help us understand what affects the size of a horse’s brain. The most obvious difference is the size of the horse – smaller horses tend to have smaller brains. This doesn’t seem to affect the overall intelligence of the animal though. In fact, ponies are often regarded as more intelligent than horses.

One factor affecting the size of the horse’s brain has been identified, and that is evolution. Amazingly, horse’s brains are gradually shrinking! It is believed that over a very long period of time, horses’ brains have shrunk by up to 16%.

Horse Brain, Human Brain: The Neuroscience of Horsemanship

It is impossible to identify why this has happened. The main factor is thought to be the domestication of horses. Basically, they just don’t need to think for themselves as much anymore! Another theory is that the breeding of horses to maintain characteristics has led to a gradual reduction in the size of the brain.

When the brains of domesticated horses are compared to wild horses, the wild brains are up to 30% larger. However, this doesn’t mean that our pet horses are not as intelligent as their wild counterparts! This reduction in brain size is most likely due to them no longer needing the parts of the brain which are required for them to survive in the wild.

Does The Size Of Horse Brain Matter?

Whether the size of a brain makes a difference to the intelligence of a creature is not entirely clear. Some scientists think that the level of intelligence increases if the size of the brain in proportion to the body increases, but others disagree.

The brain of a horse is smaller than the brain of a human, even though the horse is a larger animal. A horse’s brain accounts for about 0.1% of the overall body weight, and the human brain is 2%. But does this mean that humans are more intelligent than horses?

Unfortunately, we have no way of working this out! Intelligence can be measured in many different ways. Even though humans are the dominant species, this doesn’t mean we are cleverer than horses. It has been shown that horses are not as skilled at reasoning and problem solving as humans. However, many of us know a pony who can break free from a seemingly escape-proof field!

Are Horses As Intelligent As Humans?

Horses have retained many instinctive behaviors which humans have lost. The parts of the brain which control these instincts are much more highly developed in horses. For example, horses are prey animals and must always be ready to flee from potential predators. Therefore, the part of the brain which controls movement and coordination – the cerebellum – is much more developed in horses than humans.

Other scientists have compared the brain size of horses to humans at different ages. They have concluded that the horse has a brain the size of a human child, with the mental capability of a 12-year-old. In the past, horses have been taught to perform basic math, reading, and even spelling exercises!

When you think about horses, you realize that they are intelligent but in very different ways to humans. We communicate by talking, which normally makes it very easy to get our point across. Horses however need to use a variety of different and very subtle ways to communicate, which is much more complex than our use of language. Try and explain how you are feeling without using words and you will see how difficult it is!

Are Horses As Intelligent As Humans

One final part of the equine brain which is highly developed is the area that processes scents. When a horse sniffs at something, the information he can gain from this is far more complex and informative than anything we could imagine. So, we humans might be able to write poetry or solve puzzles, but we can’t figure out what is happening a mile away just by smelling the breeze!


So, as we’ve learned, horse’s brains are relatively small in size compared to humans.  However, with brains size doesn’t always matter, and horses are generally considered to be quite intelligent. They also have highly developed areas of the brain for important skills such as analyzing smells and fleeing from predators.

We’d love to hear your thoughts on the size of horse’s brains! Perhaps your pony is an absolute genius? Or maybe your horse does the most stupid things, and you wonder if he has a brain at all?! Please add your comments below!

Related Posts