In some ways, anthropology can be understood as a discipline that takes this question as its focus.
Usually, this would be illustrated by anthropological studies of the things like the origin of human language, life in the earliest cities, or how different societies experience and account for changes that come with aging.
But there are other things that are fundamental to our contemporary understanding of what it means to be human. One of these that is making news today: keeping pets.
BBC is reporting new archaeological evidence for the keeping of pets in Great Britain. Perhaps surprisingly, the animal in question is not one of the fluffy furry kind that are the epitome of our image of pets today. Instead, the researchers found evidence of a pet tortoise, and use that to argue for a profound shift in attitudes towards animals in the 19th century.
The lead archaeologist, Richard Thomas of Leicester University, argues that the tortoise bone discovered at Stafford Castle is evidence of "ordinary people" keeping animals "because they were fond of them", not, as with previous recovery of turtle bones in sites as old as the 17th century, understood as kept for food.
There are assumptions here that are worth some unpacking.
It is hard to separate fondness for animals from desire for an animal as an object for display. Our contemporary understanding of pets is very much based on the idea that humans and their companion animals are bound by ties of affection. But at the same time, pets are status symbols. There are fashions in the consumption of specific breeds of dogs and cats that have less to do with the intimate relations between individual pets and people, and more to do with how other people will react to the animal on the leash, or in the pet carrying bag.
The reference to "ordinary people" is a reminder that there is actually a long history of the wealthy and powerful keeping animals in collections. Examples have been studied in societies as distant as ancient Egypt, the Mexica or Aztec (by art historian Amara Solari), and the Japanese Shogunate (by historianSteven Laver). We don't talk about these as examples of pets, I would argue, because these animals were not kept out of affection nor did they routinely form one-to-one relations with their owners.
Observations like these call attention to taken-for-granted aspects of pets in contemporary global culture. A pet today is by definition an animal kept for no practical reason, because of "fondness", in a relationship with a specific person or persons.
Understanding human-animal relations today engages researchers across disciplinary lines. The Wikipedia page for anthrozoology, started in November of 2005, describes it as an "emerging field". The website Antrozoology.org, dedicated to this research, is about as old. So we can consider the recent intensification of this research as about five or six years old.
As an academic interdiscipline, anthrozoology is older; we need to look back more than two decades to when the journal Anthrozoos published its first issue in 1987. The sponsoring International Society for Anthrozoology, founded in 1991, says on its homepage that "Dramatic changes in people's attitudes towards animals and their treatment have occurred in the last 20-30 years" and that it serves a"growing community of scholars and scientists".
That community decidedly includes anthropologists. As Donald Joralemon of Smith College, commenting on a course he taught earlier this year said, "I wanted students to have a chance to think about those animals that we invite into our homes to forge close relationships with them".
Some of those relationships are very old.
According to a 2009 article in the journal Anthrozoos, ever since there were farmers in Neolithic Europe, people have been encouraging small felines to help take care of rodent problems that followed. The discovery of the bones of a cat in a 9500 year old Neolithic grave in Cyprus was publicized in 2004 as the "oldest 'pet cat'". Since cats are not native to Cyprus, the animal-- probably an African wildcat-- had to have been brought there by people. This, plus its deliberate burial with a human being, led the investigators to describe it as at least "pre-domesticated". The Anthrozoos article argues that cats were only "fully domesticated" in pharaonic Egypt, where selective breeding of imported wildcats occurred.
More than cats, dogs are the model animal for discussions of the incorporation of animals in human society.
Genetic research covered by the BBC in 2002 led researchers to argue that almost all dogs today descend from ancestors domesticated near China about 15,000 years ago. This research still has to be reconciled with a 2009 article in the Journal of Archaeological Sciencethat argued for the existence of dogs in Paleolithic Europe around 32,000 years ago, part of a long line of research summarized ably by Kris Hirst, predicated on the idea that dogs and wolves diverged when dogs began hanging out with early humans in ice age Europe.
Hirst suggests it is possible that the very old dogs in Europe were more independent of people than those today, more like cats than modern dogs, with their exemplary orientation toward humans. In this sense, the dogs and cats actually experienced different processes of domestication, and while we may include them in one category of pets, that is a human-centered view that ignores differences in cat and dog experiences of humans.
The BBC article about genetic studies pinpointing possible dog origins near China not long before the beginning of the Neolithic also reported on studies of dog cognition, finding that domesticated dogs today are extremely well attuned to cues from human beings:
"During domestication there was some kind of change in their cognitive ability that allowed them to figure out what other individuals wanted using social cues. The biggest surprise was the puppies - even as young as nine weeks old, they're better than an adult chimpanzee at finding food."
This should not be surprising to anthropologists. In the 1960s Claude Levi-Strauss talked about how people refer to and think about dogs, as subjects -- like people -- forming "part of human society". What we didn't perhaps realize was how literal that metaphor really was.