Thanks to our large brains, humans and non-human primates are smarter than most mammals. But why do some species develop large brains in the first place?
The leading hypothesis for how primates evolved large brains involves a feedback loop: smarter animals use their intelligence to find food more efficiently, resulting in more calories, which provides the energy to power a large brain. Support for this idea comes from studies that have found a correlation between brain size and diet – more specifically, the amount of fruit in an animal’s diet.
