Because lesbianism, as described by sexologists of the late 19th and early 20th centuries, was treated overtly in a number of novels of the 1920s, while earlier literature seemed seldom to recognize its existence, it appeared that what had been a taboo subject suddenly "came out of the closet" in a liberal and sophisticated era. In fact, fiction of earlier eras often dealt with love between women in the most romantic and positive terms. The fiction of the 1920s was no more frank about affection between women than its predecessors, but it differed from earlier work by depicting women who loved other women as congenitally abnormal, neurotic, peculiar, or outcast. These changes in the literary view of love between women came about because the spread of sexology "wisdom" created a hitherto seldom acknowledged category of abnormality. Women's increasing economic independence opened the possibility of permanence in such relationships, posing an ostensible threat to heterosexuality. And the new interest in companionate marriage encouraged heterosociality and heterosexuality as it had not been encouraged before, to the exclusion of love between women.