Sentence:  But even less disgruntled observers have insisted that pain and un-pleasure are more common in dreams than pleasure: for instance, Scholz (1893, 57), Volkelt (1875, 80), and others. Indeed two ladies, Florence Hallam and Sarah Weed (1896, 499), have actually given statistical expression, based on a study of their own dreams, to the <WSD>preponderance</WSD> of unpleasure in dreaming. 
Meaning of the word marked with <WSD> tags:  Excess or superiority of weight, influence, or power, etc.; an outweighing.