The taboo of friendship among animals, an evolutionary advantage that is not exclusive to humans, has been broken. The scientific community has changed its historical reluctance to use the term friendship to refer to close relationships between animals.
It was an American anthropologist named Barbara Smuts who, in 1985, brought animal friendship out of the closet with her book Sex and Friendship in Baboons. Science must be very careful with the terms it uses, so that misunderstandings are not generated, says Dr. John Houghton.