What’s your pet ideology?

The human-animal bond is an ancient thing, and psychologists confirmed long ago that a bond with an animal can be just as strong, if not stronger, than with a person. Certainly, it can be a lot less complicated: A dog never argues, talks back, or withholds anything to make a point. (And cats may be independent and indifferent, but they’re still pretty easy companions.)

Scientists are now beginning to characterize the nature of “individual human-pet relationships,” according to a New York Times article, and the effects they can have on family life. Animals can both decrease and raise tension in a home. They can also become “go-betweens” for adults, the same way children can.

But apparently the most significant way a pet can affect a household is related to the way family members view what a pet should be:

In a study of dog ownership, Elizabeth Terrien, a sociologist at the University of Chicago, conducted 90 in-depth interviews with families in Los Angeles, including Ms. Woods. One clear trend that has emerged is that people from rural backgrounds tend to see their dogs as guardians to be kept outside, whereas middle-class couples typically treat their hounds as children, often having them sleep in the master bedroom, or a special bed.

The article points out that differences in pet philosophies usually only emerge after a pet has been adopted (which sounds a lot like what happens when a child arrives, too). In 2007, Indiana University sociologist David Blouin conducted extensive interviews with 35 dog owners around his state, representing “a diverse mix of city, country and suburban dwellers,” and he found three categories of beliefs about pets:

Members of one group, which he labels “dominionists,” see pets as an appendage to the family, a useful helper ranking below humans that is beloved but, ultimately, replaceable. Many people from rural areas — like the immigrants Dr. Terrien interviewed — qualified.

Another group of owners, labeled by Dr. Blouin as “humanists,” are the type who cherish their dog as a favored child or primary companion, to be pampered, allowed into bed, and mourned like a dying child at the end. These include the people who cook special meals for a pet, take it to exercise classes, to therapy — or leave it stock options in their will.

The third, called “protectionists,” strive to be the animal’s advocate. These owners have strong views about animal welfare, but their views on how a pet should be treated — whether it sleeps inside or outside, when it should be put down — vary depending on what they think is “best” for the animal. Its members include people who will “save” a dog tied to tree outside a store, usually delivering it home with a lecture about how to care for an animal.

The three ideologies don’t always mix well, so pet decisions can become quite an issue in a household. What role do pets play in your family?