Animal sexual behaviour however, is proving to be false as, "most hormones don’t influence behaviour directly. Rather, they affect thinking and emotions in variable ways (Azar, 40)." There is much more involved in sexual behaviour in the mammalian animal than oxytocin and vasopressin can explain. It is often assumed that animals do not have sex for pleasure, or alternatively that humans, pigs, bonoboes (and perhaps dolphins and one or two more species of primates) are the only species that do. This is sometimes stated as "animals mate only for reproduction". This view is considered a misconception by some scholars. Jonathan Balcombe argues that
The Lives of Animals her honor. In her first lecture, Costello also moves to reject reason as the preeminent quality that separates humans from animals and allows humans to treat animals as less than the equals of humans. She proposes that reason might simply be a species specific trait, "the specialism of a rather narrow self-regenerating intellectual tradition ... which for its own motives it tries to install at the center of the universe." At the same time that Costello rejects reason as the premier human distinction, she also challenges the assumption that animals do not possess reason. Her argument rests on the fact