The neural machinery may be similar among mammals, but humans haven't bred cats to act the same way as dogs. Humans have kept pet cats for about 5,000 years, whereas estimates for dog domestication date as far back as 32,000 years ago. Given that extra time, dogs "may have been heavily selected to ‘show' behaviors that we think are empathic," Mikel Delgado, an animal cognition expert, tells The Dodo. And simply because dogs can mimic "human emotional behaviors," she says, "I don't think we can ‘know' that dogs love us."
That's why she believes studies that compare the affections of cats and dogs are flawed. Reports that indicate cats are detached or inattentive but dogs are friendly, Delgado points out, take place outside the home, in environments much more stressful for cats.
And although pet owners can't look to studies of brain chemicals to learn about feline affection, they can rely on something easier to observe: cat behavior, from rubbing to blinking to licking.
As Bradshaw writes in the Washington Post, many cat behaviors are linked to affection, but an upright tail is the key: