Well-known advocates include primatologist
Jane Goodall, who was appointed a goodwill ambassador for the
United Nations to fight the
bushmeat trade and end
ape extinction;
Richard Dawkins, former Professor for the Public Understanding of Science at
Oxford University;
Peter Singer, professor of philosophy at
Princeton University; and attorney and former Harvard professor
Steven Wise, founder and president of the
Nonhuman Rights Project (NhRP), whose aim is to use U.S. common law on a state-by-state basis to achieve recognition of legal personhood for great apes and other self-aware, autonomous non-human animals. In December 2013, the NhRP filed three lawsuits on behalf of four chimpanzees being held in captivity in New York State, arguing that they should be recognized as legal persons with the fundamental right to bodily liberty (i.e. not to be held in captivity) and that they are entitled to common law writs of
habeas corpus and should be immediately freed and moved to sanctuaries. All three petitions for writs of habeas corpus were denied, allowing for the right to appeal. The NhRP is appealing all three decisions. Goodall's
longitudinal studies revealed the social and family life of chimps to be similar to those of human beings. Goodall describes them as individuals, and claims they relate to her as an individual member of the clan. Laboratory studies of
ape language ability revealed other human traits, as did
genetics, and eventually three of the great apes were reclassified as
hominids. Other studies, such as one done by Beran and Evans, indicate other qualities that humans share with non-human primates, namely the ability to self-control. In order for chimpanzees to control their impulsivity, they use self-distraction techniques similar to those that are used by children. Great apes also exhibited ability to plan as well as project "oneself into the future", known as
"mental time travel". Such complicated tasks require self-awareness, which great apes appear to possess: "the capacity that contribute to the ability to
delay gratification, since a self-aware individual may be able to imagine future states of the self". The recognition of great ape intelligence, alongside the increasing risk of great ape extinction, has led the
animal rights movement to put pressure on nations to recognize apes as having limited
rights and being legal "persons." In response, the
United Kingdom introduced a ban on research using great apes, although testing on other primates has not been limited. Writer and lecturer Thomas Rose argues that granting legal rights to non-humans is not a new concept. He points out that in most of the world, "corporations are recognized as legal persons and are granted many of the same rights humans enjoy, the right to sue, to vote, and to freedom of speech."
Gary Francione questions the concept of granting personhood on the basis of whether the animal is human-like (as some have argued) and believes
sentience should be the sole criterion used to determine if an animal should enjoy basic rights. He asserts that several other animals, including mice and rats, should also be granted such rights. ==Interpretation==