What makes a great a spiritual leader? Is it nature or nurture or something else?

Two premises presumed for my question: 1. The 14th Dalai Lama is an especially sincere spirit 2. Reincarnation, beyond the scientific eg recycling of atoms / culture / dna, is an incorrect idea. Is the 14h Dalai Lama's charisma created by being raised as a spiritual leader? Are all Tibetans especially sweet souls? Is it both or neither, but rather great luck? I am trying to tease out nature & nurture, and squeeze out the supernatural!