Why are we naturally inclined to follow our authority

Followership is the default phenomenon of human brain.

Explanation:

The concept of follow ship can be seen at an early stage of infancy when babies tend to mimic their mothers' facial expressions and, from around three months of age, they can follow their mothers' eyes and it worked as an evolutionary survival strategy for them. Sigmund Freud was the very first to give some rationale of how the unconscious motivations of the follower work. The motivations of followers classified into two groups which are rational and irrational. They have to do with our hopes of winning money, status, power, or entering a meaningful enterprise by following a great leader. There are irrational motivations that lie outside the sphere of our knowledge and therefore beyond our capacity to monitor them.

because the early people found out about it.