What is the main conflict in Sturgeon's short stories?

One of Sturgeon's main contributions to science fiction in the 1940s and 1950s (a contribution he was able to make perhaps because he frequently wrote other kinds of stories and thus lacked the narrow "ghetto" mentality of many science fiction writers) was to make psychological conflict central to the short story. Instead of characters who exhibit their creator's cleverness at inventing and solving intellectual puzzles (e.g. Asimov's robot stories) or who perform melodramatic feats of derring-do (as in countless "space operas"), Sturgeon emphasizes characters who confront some ethical or emotional dilemma. His protagonists are tormented by loneliness or frustrated love; they suffer from the bigotry and narrow-mindedness of society; they learn to come to terms with their own gifts and limitations.