The fact that Professor Vaughn is interested in such phobias that occur as a result of natural things, this is evolutionary psychology.
This is a branch of psychology that aims to find out why humans relate to the environment in a certain way.
Phobias resulting from natural occurences like snakes, will fall under evolutionary psychology because it relates to a human interaction with the environment.
Find out more on evolutionary psychology at https://brainly.com/question/25207796.