I caught a 10 incher that thought he weighed 5 pounds.

I don't think they know they are fish.

I guess I sort of emphasized the wrong point. I was more so wondering how bass end up in schools if similar average size, or the biggest males and females often pair up together, if they have no ability to gauge size. I know they don’t reason and think about things, but I wonder if there is some sort of intuition they have to stay with similar sized fish.

I've seen times where they seem to be schooling up by size. It's possible that they can somehow tell they're among other fish of roughly equal size.

7 minutes ago, The Maestro said:

I've seen times where they seem to be schooling up by size. It's possible that they can somehow tell they're among other fish of roughly equal size.

I think it's more habit. They school up as fry - safety in numbers - and even as the numbers decline due to predation or whatever - they stay with their 'year group' for as long as possible. That's why they school up by size - it's just the group they hatched with and they stay together by habit.

Or the same age, and hatched in the same overall area?

Apparently not....lol