Vulcans are the native intelligent life of Vulcan and are highly intelligent and resourceful, driven by a strict philosophy of total logic and emotional suppression. Biologically, Vulcans retain volatile emotions that manifest uncontrollably every seven years during a highly secretive mating period known as Pon farr. They possess limited telepathic abilities, such as the Vulcan mind-meld, and like most humanoids exhibit ethnic diversity based on skin tone.