Whenever anyone asks with any degree of seriousness whether it’s possible that animals experience the same emotions that we do, I wonder then whether or not such people experience the same higher cognitive functioning that I do. How could anyone possibly behold the absolute joy a dog expresses upon the return of its beloved master, or the luxurious pleasure a cat takes in a scratching of its jowls, and not find in these self-evident raptures any evidence for the experience of emotion?
Such crass obtuseness reveals a sad capacity for humans to be completely blind to their own base emotions. Jealousy, for example, if it is more intense anywhere than it is among dogs seeking the attention of the same owner, might be rivaled by two or more young women seeking the eyes of the same guy. Their ensuing spats aren’t known as cat fights for nothing.
It isn’t outside the realm of possibility that no animal on Earth, not even the smallest bug, acts without the guidance of emotion. Social or solitary, most creatures have to fear for their lives and for the lives of their young as threats approach; many may thus know loyalty and love; most should desire sex; all ought hunger for sustenance; and more than a few do compete for status and respect.
Perhaps their emotions differ from ours more in strength, than in kind. But the evolution of language skills, particularly written language, has so distinguished us among our animal brethren that some of us can now persuasively talk ourselves out of seeing any relation at all.