Rape, Forced and Aggressively Coerced Copulation

Abstract

Forced copulation is a type of sexual coercion, which theoretically occurs when the fitness interests of a female and a male conflict over a copulation or mating. The term “rape” is now most often used to describe forced copulations in humans, while the term “forced copulation” is a description of motor acts of non-human animals without the legal meanings humans associate with the term “rape”. Forced copulation in nonhuman animals occurs when males use aggression or intimidation to force a female to copulate against her will. In nonhuman organisms, investigators rely on signs of female unwillingness to infer that a copulation is forced. Forced copulation occurs in many taxa, including mollusks, insects, fish, reptiles, mammals, and the 3% of bird species that have intromittant organs. Female unwillingness signals are often dramatic; male force can maim or kill females and reduce female lifespan; thus female unwillingness or direct physical resistance is a reliable basis for assigning a copulation to the category of ‘forced copulation.’ Four hypotheses potentially explain the adaptive significance of forced copulation: the inferior male hypothesis, the by-product hypothesis, the creation of a dangerous environment hypothesis, and the Killing Time Hypothesis. These hypotheses potentially explain why males attempt to and do force females to copulate.