Final answer:
Chimpanzees and bonobos are nonhuman primates that use force to copulate. Chimpanzees exhibit aggressive behavior, while bonobos engage in frequent and variable sexual behavior.
Step-by-step explanation:
Nonhuman primates that use force to copulate include chimpanzees and bonobos. Chimpanzee groups are intensely hierarchical, and males often display aggression, including forceful copulation. Bonobo groups are mostly egalitarian, and they engage in frequent and variable sexual behavior, including various forms of genital contact. Some researchers believe that sexual contact helps build social bonds and ease conflicts in bonobo groups.