The capacity to reason is arguably the principal differentiating factor between humans and other animals. Some species exhibit some limited ability to draw inferences, but no other animal comes even close to the ability of humans to make long sequences of inferences in order to deduce a particular conclusion.
Biological anthropologists generally agree that humans evolved reasoning to facilitate hunting together as a group; however, there are many other
kinds of animal that hunt in packs, and yet reasoning is unique to humans.
Therefore, in order to explain reasoning, it is not enough to consider how it
was beneficial to us; we also need to consider what enabled reasoning to
emerge specifically in humans as opposed to any other species.
I have a hypothesis which attempts to explain how reasoning emerged in humans, and why it is unique to humans.