How do body and brain size guide intelligence?

Animal Brains [All Ages]

Opening Questions

Do you think a bigger brain makes you more intelligent?

Do you think the brains of other animals will be as folded as the human brain?


Part 1: Show the audience the pictures of brains and animals in the Image Gallery below and ask them to match the brain to the animal. It may help to point to the brain and let the audience call out which animal it belongs to or raise their hands to respond.

Part 2: Show the audience the picture of the horse and human brain together and ask them if they notice any differences. Did they expect the horse brain to be bigger than the human brain because horses are so much bigger? (The horse brain is the smaller one on the left).

Discussion Points


Q: Why aren’t the brains of the smaller animals as folded as the human brain is?

A: The folded part of the brain, the cortex, is responsible for all our very clever thinking. These animals rely largely on instinct so do not need such complex brains. Animals with more folded brains tend to be more sociable and to be able to learn more as they grow up.


Q: What do you think the relationship is between brain size, cortical size (as measured by how folded it is) and intelligence?

A: Although brain size often (but not always) gets bigger with body size, it is the area of the cortex that makes the brain clever, not just its overall size. If you folded out your cortex it would be about 4 times bigger than the cortex of a chimpanzee (our closest relative), 8 times bigger than the cortex of most other monkeys and 16 times bigger than that of a rat.

Image Gallery