According to the information in the book, Companion Animals and Us, by Anthony L. Podberscek, Elizabeth S. Paul, and James A. Serpell, there has been an incredible growth in studies of the human-companion animal interactions over the past 30 years. Pets are in at least half of the homes in Western countries. And the questions being researched include: what is so special about the relationships people have with their pets? Are humans very different from the ancients in how we feel about animals? What can we learn about ourselves and our relationships with people from our relationships with pets? Are pets good for our health? Do pets help us be more compassionate with other people? The research done over these years involves fields that include anthropology, history, psychology, sociology, and human and animals medicine. In short, researchers are trying to figure out what is so special about our relationships with our pets.