The size of the brain is not an actual indication of how smart a creature is. Take big brown bears as an example. Their brains are much bigger than the human brain, but that doesn’t make them smarter than us, while chimpanzees have much smaller brains and are smarter than bears.

The size of the brain does not determine the complexity or the development of certain areas. Humans, for instance, have a much more developed language faculty. And there are other factors at play such as social and emotional intelligence, making intelligence something difficult to measure.

IQ tests measure one specific form of intelligence and are not an indication of how overall intelligent you are

Another myth is that IQ tests are an accurate measurement of intelligence. Normal tests measure things like executive function or planning, verbal skills, reading skills, and the like.

However, these measurements are highly influenced by the conditions of the test and measure only certain aspects of intelligence. Intelligence is something that is developed through education and training, and while there are people who are prodigies, it is very hard to say what determines that. We are all individuals with different talents and aptitudes. IQ tests measure one specific form of intelligence and are not an indication of how overall intelligent you are.