Animal rights leader Peter Singer, the founder of the Great Ape Project, and the leading animal right organization PETA who were behind the Spanish parliaments extending of rights to apes support sex between animals and humans.
In a 2001 review of Midas Dekkers's Dearest Pet: On Bestiality, Singer stated that "mutually satisfying activities" of a sexual nature may sometimes occur between humans and animals and that writer Otto Soyka would condone such activities. Singer explains Dekker's belief that zoophilia should remain illegal if it involves what he sees as "cruelty", but otherwise is no cause for shock or horror. However, Singer does not claim to endorse the views of either Dekker or Soyka, merely to be explaining them. Singer believes that although sex between species is not normal or natural, it does not constitute a transgression of our status as human beings, because human beings are animals or, more specifically, "we are great apes". Some religious individuals and animal rights groups have condemned this view, while the animal rights organization PETA has expressed cautious support.