looking animals in the eye

I see all sorts of posts and threads about animals eyes, but I’ve always wondered about this and have never seen much on it: Why do we look at another being in the eyes in the first place? Why does an infant look into the eyes of another person? Why does a stupid cat (redundant, I realize) look at a person in the eye, or an even lower animal such as, say, a reptile? What IS it about the eyes that seem to be a proxy for the entire person? What general topic does this question fit into? Is this biology? Philosophy? Ceramics? ???

Looking an animal or person in the eye can be an act of aggression. Carnivores/hunters stare at something when they are trying to judge the distance so that they can attack it.

When two predators look each other in the eye it may be to establish dominance and/or trust. Your cat may be looking back into your eyes in order to judge your intentions and flee if necessary.

Eyes are our only directional non-contact sense. To see something you have to aim your eyes at it. And the way that eyes are made, you can see where someone else’s are looking. Very valuable in a confrontation. For animals eye contact usually means aggression. Not sure why eye contact has taken on so many important significance in so many contexts (combat vs. romance). In the US strong eye contact is supposed to be desirable in doing business (e.g., job interview), but I’ve heard that it’s offensive in Japan.

I understand that the question, “why?” is ultimately unanswerable in many cases, but that’s what I’m trying to understand. A baby looks an adult human from eyes to eyes. What is happening during that moment? The child clearly does not know that eyes are the “only directional sense,” nor anything else. Neither do dogs. Yet we find ourselves connecting that way. Yes, it has meaning, but how does that happen only when we’re looking AT EACH OTHER? I mean, when a baby looks at your arm, he’s not looking at YOU. Nor, are you looking at him when you look at his arm. But when you lock gazes, you are looking at each other. How does that happen in a days-old infant? How does it happen between humans and animals? Ya know?