Wikipedia on a 1953 novel by Theodore Sturgeon:

"The novel concerns the coming together of
six extraordinary people with strange powers…."

Review of the novel by Ted Gioia at Conceptual Fiction :

"If there is a flaw to More Than Human , it comes from
the writer’s desire to achieve more than fiction. If you 
think that sci-fi books don’t pay attention to deep
inner meanings, you will be surprised by the conclusion
to this work, in which Sturgeon reaches for something
bigger than a story of this scale can deliver."

Background: Sturgeon's novella Baby is Three  (1952).

See also  6!  in this journal.