From the planet Vulcan, they are the race that the Romulans split from and used to be a very passionate and violent people. The philosopher, Surak, changed this about 2000 years ago when he introduced logic and persuaded people to reject their emotions. The Vulcan society in now purely based on logic.
In the past Vulcans killed to win their mates and even now Vulcans revert to ancient mating rituals. This is apparently is the result of total rejection of emotion. When Vulcans are around seven, a mate is selected for them by their parents and the two are linked telepathically. When they come of age, the two are joined in marrage rituals. Another result of control of emotion is Pon farr which arrives every seven years and involves a period of total emotional abandon.
Vulcans display great physical strength on earth normal planets due to the fact the Vulcan has a higher gravity. They also have more acute hearing because of Vulcan has a thinner atmosphere. Vulcan also has a very intense sun which has caused the Vulcans to develop a secondary inner eyelid which allows them to survive intense light with no damage to their eyes.
Vulcans have the a telepathic ability but this is quite limited and a Vulcan usually has to be in physical contact with the subject.
