Are [animals] not furnished with most feelings similar to our own? They indisputably evince in an eminent degree most of the same passions. Things which affect us, generally seem to affect them in the same way; and at least the following sensations and passions are common to both, viz. hunger, desire, emulation, love of liberty, playfulness, fear, shame, anger, and many other affections though they are destitute of the power of laughter. But little occasion have they to exercise such a faculty!

The soul is the same in all living creatures, although the body of each is different.

[T]he young and the old of widely different races, both with man and animals, express the same state of mind by the same movements.

Men have had the same origin as other animals; they have the same general architecture of body and mind; and they have the same destiny. And they stand on the same general level of ethical claim and obligation.

There is no fundamental difference between man and animals in their ability to feel pleasure and pain, happiness, and misery.

All cultures share certain commonalities, stored in our genetic inheritance. Anthropologists tell us that all cultures distinguish colors. When they do, all cultures begin with words for white and black. If the culture adds a word for a third color, it is always red. All humans, for example, register the same basic facial expressions for fear, disgust, happiness, contempt, anger, sadness, pride, and shame. Children born without sight display emotion on their faces the same way as children born with sight. All humans divide time into past, present, and future. Almost all fear, at least at first, spiders and snakes, creatures that threatened their Stone Age ancestors. All human societies produce art. They all disapprove, at least in theory, of rape and murder. They all dream of harmony and worship God.

Most of the more complex emotions are common to the higher animals and ourselves. Every one has seen how jealous a dog is of his master's affection, if lavished on any other creature; and I have observed the same fact with monkeys. This shews that animals not only love, but have the desire to be loved.

I believe that the best way to create good living conditions for any animal, whether it's a captive animal living in a zoo, a farm animal or a pet, is to base animal welfare programs on the core emotion systems in the brain. My theory is that the environment animals live in should activate their positive emotions as much as possible, and not activate their negative emotions any more than necessary. If we get the animal's emotions rights, we will have fewer problem behaviors. (p3)

People and their pets connect via shared brain structures that predate the development of the human frontal cortex with its apparatus of language and rationality. Animals and humans interact from their respective limbic systems, the brain’s emotional parts. Unlike people, animals are acutely sensitive to messages from the limbic brain — both their own and that of their owners.

If the original essence of the thing which we fear could confidently lodge itself within us by its own authority it would be the same in all men. For all men are of the same species and, in varying degrees, are all furnished with the same conceptual tools and instruments of judgement.

We hold these truths to be self-evident that all P-brains are created equal.

Because other mammals have expressions, does that mean they have feelings — a subjective experience of the emotional states they display? That idea was scientifically risible not so long ago. Now some emotion scientists endorse the proposition that other mammals possess emotional consciousness — that they feel. This reversal delights animal advocates eager to make an argument for panprotoplasmic parity. But when the zoophile Mark Derr writes, “The question of whether animals possess consciousness, intelligence, volition, and feelings has long been settled in the affirmative,” he must be reporting the consensus from a species other than our own. Animals may have decided the matter to their own satisfaction, but human beings, as far as we know, are still debating it.

But in such perfect Animals as Sheep and Oxen, in whom the Heart, the Brain and Nerves differ so little from ours, and in whom the Separation of the Spirits from the Blood, the Organs of Sense, and consequently Feeling it self, are the same as they are in Human Creatures; I can't imagine how a Man not hardened in Blood and Massacre, is able to see a violent Death, and the Pangs of it, without Concern. In answer to this, most People will think it sufficient to say, that all Things being allow'd to be made for the Service of Man, there can be no Cruelty in putting Creatures to the use they were design'd for; but I have heard Men make this Reply, whilst their Nature within them has reproach'd them with the Falshood of the Assertion.

The truth is, Homo sapiens sapiens is pretty much the same the world over, regardless of skin color or technological development. Racists and provincial types have problems with this fact, but it is a fact. All mortals have the same potential, and only chance determines who’s playing a spinet or who’s clubbing dinner to death with a big rock. And, you know what? Mortals adapt to the environment in which they’re placed. Switch babies between savages and technologicals, and nobody notices! I know, because I’ve seen it done. I’ve seen the son of a club-carrying cave dweller fuming because his accounting software wasn’t quite adequate for his needs. All humans have the same brain package.