Sex has become a more acceptable topic of discussion in society and the media, while masturbation, a way of self discovery and pleasure, continues to be labeled as taboo. According to Amy Popillion, resident sexpert and senior lecturer at Iowa State, masturbation for both males and females was historically considered a moral problem. During the 18th and 19th centuries it was even considered a mental and physical illness. In fact, anti-masturbation gear, such as the pelvic constrictor for men, was invented to prevent the wearer from unconsciously masturbating while they were sleeping.