"Daley went on to detail a 2010 study that coded incidents of aggression in best-selling 2004 and 2005 porn videos. She noted that 88 percent of scenes showed verbal or physical aggression, mostly spanking, slapping and gagging. (A more recent content analysis of more than 6,000 mainstream online heterosexual porn scenes by Bryant Paul and his colleagues defined aggression specifically as any purposeful action appearing to cause physical or psychological harm to another person and found that 33 percent of scenes met that criteria. In each study, women were on the receiving end of the aggression more than 90 percent of the time.)"