The erotic thriller is a film subgenre defined as a thriller with a thematic basis in illicit romance or erotic fantasy. Though exact definitions of the erotic thriller can vary, it is generally agreed "bodily danger and pleasure must remain in close proximity and equally important to the plot." Most erotic thrillers contain scenes of softcore sex and nudity, though the frequency and explicitness of those scenes can differ from film to film. Erotic thrillers emerged as a distinct genre in the late 1980s, bolstered by the popular success of Fatal Attraction in 1987 and continuing into the early 1990s. Studio films of this "classic period", such as Paul Verhoeven's Basic Instinct, were box office successes, helmed by big-name directors, and starred high-profile actors. The popularity of the genre spawned a lucrative cottage industry for the burgeoning home video and cable television markets. By the end of the 1990s, cultural changes and the rise of the Internet led to the decline of the genre's popular appeal and production volume. According to British film studies professor Linda Ruth Williams, "Erotic thrillers are noirish stories of sexual intrigue incorporating some form of criminality or duplicity, often as the flimsy framework for onscreen softcore sex". The thriller film genre contains subgenres other than the noir crime film and murder mystery, including the psychological thriller, or suspense stories of illicit romance and sexual obsession. Thus, the erotic thriller participates in several genres and film styles at once, such as film noir, romance, and the thriller, taking narrative and stylistic elements from each. Because the erotic thriller combines various genres, pinning down the exact formula for an erotic thriller can be difficult. Though academics and writers on the subject encapsulate the erotic thriller film differently, the overlapping of the suspense thriller, romance, and softcore sex film is the unique domain of the erotic thriller.