Why aren't animals with bigger brains smarter than us?

Bigger isn't always better. Sometimes how you use it is more important than what you've got. read more

Your question has a false premise. Animals with bigger brains are not smarter than us, whales and elephants, while extremely intelligent, have bigger brains and are demonstrably not smarter than us. Intelligence is often determined by a few things working in conjunction, not just brain size: Use of language. read more

Second, relative size is more important than absolute size. The ratio of brain weight to body weight is about 1: 5000 for fish, 1: 220 for birds and 1: 180 for mammals, with the most intelligent species generally having the highest ratio. read more

Even within human populations, brain size scales with body size (males are larger and tend to have larger brains), but "intelligence" correlates weakly if at all with brain size in adults. The other half of the problem is trying to extrapolate some metric of intelligence that applies to other species. read more