Neuroscientists have studied for decades how and why humans appear to be smarter than all other animals on Earth.

Factors such as brain size and neurological makeup do not alone determine this intelligence.
For example, male human brains are larger than female brains, but there is no difference between male and female IQs.

And elephants have larger brains than humans, but no evidence supports that they are smarter than us overall. And small minds can be super bright too; ravens show an incredible intelligence, despite having tiny "bird" brains.

What makes humans so much smarter?