Soft science fiction, or soft SF, is a category of science fiction with two different definitions, defined in contrast to hard science fiction. It can refer to science fiction that explores the "soft" sciences (e.g. psychology, political science, sociology), as opposed to hard science fiction, which explores the "hard" sciences (e.g. physics, astronomy, biology). It can also refer to science fiction which prioritizes human emotions over the scientific accuracy or plausibility of hard science fiction.Soft science fiction of either type is often more concerned with depicting speculative societies and relationships between characters, rather than realistic portrayals of speculative science or engineering. The term first appeared in the late 1970s and is attributed to Australian literary scholar Peter Nicholls. Source: Wikipedia (en)