The E'dn (also called the Eden) is the empathetic psionic wavelength humans resonate on. It is primarily empathetic in nature and directly deals with things outside of the body. Unlike the hotai the e'dn is seen as a selfless set of abilities as it is more difficult to affect or inspect the self.
The e'dn was first used by ancient humans as a communication and teaching mechanism to show and teach younger humans how to do things. It was also used for sharing and helping humans understand each other. As a highly empathetic race this allowed humans to better feel one another and led to very little fighting amid both tribes of humans and humans interacting. If there was a conflict it was settled without fighting or killing since it was easy to feel how others felt and to hurt another was akin to hurting yourself.
As humans evolved it became used for other things to expand beyond their understanding of the self and empathy. It evolved as a way to help others around them. The ability to lift things with your mind or start a fire with your mind became a highly sought after trait because it meant you could help more, you could do more for your community. And humans that had that capability were more likely to do more as well.