How Does a Sheep Brain and a Human Brain Compare?

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There are significant differences between the human brain and the brains of sheep; for instance, the human brain is larger in size and heavier when compared to a sheep’s brain. An adult human brain weighs 1,300 to 1,400 grams, while the brain of a sheep weighs in at around 140 grams. Sheep brains have less ridges and contours in comparison to human brains.

While a human brain has more of a rounded shape, a sheep’s brain is elongated. Sheep and humans have the brain stem in common, which regulates autonomic functions, such as breathing and heartbeat. Human behavior and motor control is typically governed by the cerebellum. In a sheep’s brain, the cerebellum is much smaller, which is the reason sheep have significantly less motor control and learning abilities.

The olfactory bulb is comparatively larger in the sheep’s brain when compared to the human brain, because animals need to rely more upon their senses and abilities of smell. Naturally, humans rely more on hearing and seeing. Human brains allow us to be able to think and be self-aware. Sheep brains do not have these capabilities. Metacognition and other advanced cognitive skills, such as social intelligence, planning and reasoning, are all thought to depend on a region of the brain called the prefrontal cortex, which is exclusive to the human brain.