Now there's another good question Donna! Take notes Ryan! (that is if you're serious about studying this - the group will no doubt supply you with oodles of Q&A&C/E/etc (conjecture, experience, etc.) that you may or may not think of yourself.
Are fish that school or have schooling behaviour smarter? - I can't answer that, but I can throw some stuff in to add to the equation or broaden the questioning.
While many of the fish I have had, have been of types that in a natural setting would school with others of the same or others who served a eco-preservation purpose (a mixed group all working together - we call it nature, but somewhere in experience and evolution different species did find this mixing in a group to be of use) even they were vastly different; there is
one fact that sticks out in my head about my fish specifically:
None of mine were ever in a group or had tank-mates exceeding, I believe four maybe five would be the highest number sharing a tank when I had any of those "smart ones" and most of them even less or were the sole fish in a tank. The Betta that was "smart" - he was solo. When I've had Bettas mixed with others or opposite-gender pairings with or without even "algae eaters" present - they were very "simple-minded" or otherwise living their lives solely on the most basic instincts - they didn't even do anything to indicate a more complex grasp of the cause and effect sequence of the micro-events that made up the whole sequence of them being fed. E.G. a single fish notices the approach of a human keeper, perhaps even by an internal clock that matches a timepiece for the human and/or their internal clock and/or daily routine, watches the food
container or food secured, hand open a lid or move to over the surface of the water, food offered - and in understanding, grasp/concept, whatever - reacts by "following" within the confines and arriving at the surface to eat, perhaps does a "trick" or whatever.... WHEREAS Multiple Fish, schooling types or otherwise, (with the exception of the DEs, who showed alpha and beta/ranking behaviour when it came to food aside from "tricks") have, for me, shown little to none of that recognition. Perhaps, being in a larger group, did not allow for them to "think beyond" the group and the immediate tank-environment and its presence, such as their welfare, the competition, "whatever"... I know I've seen such in canines and felines, equines and avians, and even some RPs - where the human providing the food was virtually a non-factor, they had their eyes on others - some looking to follow a leader or a majority-action or decision, staying within their
rank/position in the group and not rocking the boat, figuratively speaking. Maybe the solo-kept fish have an advantage because of lack of competition or peers, or for lack of a social-fish-network within their tank, they are in need of or feel at ease to allow themselves to "broaden their horizons" by accepting additional input/influence from factors outside of the tank (people, other animals, sounds, lighting, you name it).
I got two more Bettas yesterday. Both male, both Crowntails. One is for my son - I couldn't resist, quite possibly the greenest Betta I have found in person and my son loves GREEN. Initially he was set in his wee cup on my husband's pc desk, next to his mouse - which the brand I forget, but the mouse has a techno-tribal pattern on it that backlights in red like dye injected into a vein that then radiates into smaller vessels. I watched these fish for a long
time in the store, they weren't displaying to one another. It made sense to me, cooped up in little containers, same rivals day after day in the same type of containers - at some point the displaying becomes a waste of energy, a futile effort with no reward. But last night when that mouse did its light-up the way it did, THAT got that Betta's attention! In retrospect, I was thankful I didn't get the LED colour-changing novelty tank for my son to use - the colour-changing LEDs probably would have had that little guy wearing himself out! I haven;'t decided the fate of the second Crowntail. I got him because I liked him, but because Fizz (husband and sons decided on a name for him) - while lovely - blatantly prefers the men in the house and I don't have him "just to myself" to train "to me"; that's not a complaint. It just means that since my daughter has been vying for a fish, I may give her Fizz - and keep the other Crowntail for myself, or vice versa.
Either way each male Betta will be paired up with a human "as their very own" and it should all work out. I know that any "tricks" will be more likely to be learned with one-on-one between Betta-and-person. I have yet to find another species - that isn't an algae-eater - that I can put a male Betta with where he won't consider it competition and attack.... had many a guppy become prey-food for DEs because Bettas shredded their fins (males and females alike on the Bettas, and no gender-discrimination for the guppies either)... anyone had luck tank-sharing a Betta with anything more attractive than "bottom feeders"?????