Supermind is a science fiction novel by A. E. van Vogt first published in complete form in 1977 by publisher DAW Books. It is a fix-up of "Asylum," a short story first published in Astounding Science Fiction in May 1942.
As with many van Vogt works, the novel uses a psychological element, in this case Intelligence Quotient or IQ. The novel shows various characters whose social roles are based upon their IQ. The galactic civilization has set up an outpost on the planet Earth manned by a scientist and his daughter whose IQ are much higher than humans; however, as the novel develops, other groups within the galactic civilization emerge who are much more intelligent.
One group within the galactic civilization, the Dreegh, are similar to vampires in that they must absorb the life energies of other beings in order to survive. A space ship with a Dreegh couple arrives on Earth as scouts to determine if what is left of the Dreegh race can take over the Earth as a base and place to live thereby hiding from the galactic civilization.