Animal brains come in a wide variety of shapes and sizes, but size is a poor measure of intelligence. The giraffe brain above is nearly as large as the human brain, but good luck finding a giraffe capable of carrying a conversation.
Rather than brain size, what really seems to matter is the number of neurons and where they are located. The human cerebral cortex — the wrinkled outer layer of the brain responsible for language, reasoning, and information processing — contains 16 billion neurons, more than any other animal. This may help explain our enhanced cognitive abilities. Scientists are studying other animals to identify similarly neuron-dense brain areas and how they contribute to brain function.