Board Thread:Warhammer 40k General Discussion/@comment-9026161-20130719005722/@comment-3580035-20130823125256

Simple answer: There is no mind controlling power, so you won't find it anywhere.

Ethereals command exceptional loyalty control of other Tau, but the reasons have never been explained. The 6th ed Tau Codex has shown that technology is used to boost the command effect somewhat, but Ethereals otherwise just have some aura. It has the slightest relation to pheromones, but that is NOT the main cause (for numerous reasons).