"Dogs develop very strong, instinctive attachments to the people who feed and care for them," said Katz, speaking Wednesday from his farm in upstate New York. "Over 15,000 years of domestication, they've learned to trick us into thinking that they love us. "

What about the nuzzling? The big, adoring eyes? The wagging glee with which they greet us?

They're all part of what Katz refers to as the "opportunistic, manipulative behavior" that's second nature to dogs.

. . .

"Dogs don't 'miss' you when you go away," said Katz, whose conclusions are supported by university studies of animal behavior. "They might get anxious and confused, but don't mistake that for loneliness or mourning. As soon as they find someone else to take care of them, they forget you pretty quickly."

He added, "I don't mean to imply that dogs aren't great. I love my dogs. But I don't need to pretend that they're like people. That doesn't do them any good. Dogs are happiest when you treat and train them as dogs, not children."