That suggests that an OP has at least a rudimentary conscience. And conscience is related to the ability to love. So we might think that an OP can love in a certain way, possibly like a dog: as the C's said, Dogs feel "need" as love.
[...]
Now, there are a few people I have interacted with over long periods that I give a high probability to being OPs. What did I notice about them? The two main things I have noticed is that yes, they do seem to have a sort of "empathy" that is strictly physical based. Quite often, they are people who are fixated on "saving stray animals," or "hugging trees" etc. What is strikingly different about these people is they are unable to feel empathy for un-seeable psychic or psychological pain. They simply have no ability to conceptualize the suffering of another if it is not right out in front of them. They will cringe and weep and cry over the death or suffering of a body, but will not think twice about saying or doing something that is totally psychologically crushing to another human being.
The other thing is their total inability to learn something and transfer that learning to another situation, similar or otherwise. They learn by rote, by specific situation, and then with the context changes even slightly, they make the same dynamical errors as though there was no similarity between the one situation and the other. Unless the situations are identical, they don't seem to be able to draw comparisons.
Both of these things: inability to conceptualize and empathize with psychic suffering and inability to transfer learning, seem to relate to higher, abstract thinking as well as being able to put oneself in another's shoes in a more "imaginative" way. It's easy enough, when you see a burn victim, for your skin to "feel" it and your stomach to knot up with "kinship suffering," but when you hear about how a husband walked out on his wife on their anniversary, it takes some imagination to "get" that the wife suffered very cruelly.
Now sure, such things can be "learned" by rote. OPs can learn that most people think that when a husband abandons his wife on an anniversary, birthday, or other "significant" time, it is supposed to be a "special kind of suffering," but if you observe carefully, you will notice that this learning cannot be transferred to other specific situations.
Also, it seems that the individuals that I think are very likely OPs are VERY sympathetic to animals - sometimes moreso than to humans.
So, just some observations.