redearslider.com

I have seen it posted several times that turtles are solitary animals that don't require companionship, really only want it when they want to mate. I am only speaking from my experience but my turtles LOVE each other !
I have two female RES that are about 4 inches, they have been with me for about 2 1/2 years. They spend all their time together ( where else would they go ? ) bask on top of the other, swim together, etc.
I also have two hatchling painted who do the same exact thing, even the basking on top of one another. If they were solitary , wouldn't they spend time in opposite corners of the tank and pretty much ignore each other ?
This is not to advocate that everyone run out to get a companion turtle or even that they wouldn't be perfectly happy as an "only child ", but just to make a point that yes, they are social animals that enjoy each other's company ( unless of course, they don't ! ).
painted patience

I agree to an extent. I've seen wild turtles stacked on top of eachother and mine do it too. I think, to some degree, they enjoy the company of other animals, nomatter what they may be....until they eat them..

I think it's possible for turtles to co-exist with one another, depending on the turtle and size of the tank. And, I think since they get used to having another turtle in the tank, they will miss that turtle if the turtle is taken away. Not really miss the turtle, but miss having something familiar in the tank taken away, they don't always deal that well with changes (but who really knows).

I have more than 1 eastern painted together in a stock tank, and they do spend some time kind of following each other around---I think, though, that's because neither wants to see the other get any extra food. They will, however, spend time at opposite ends of the tank, doing whatever they do. They'll bask at the same time, but not near each other (they have a good size basking area). To me, it's not really socializing, though.

When I see turtles in the wild, they're always traveling alone. If I see several basking on a log, to me it's probably because that's the best basking spot in the immediate area.

Most of the posts about being solitary and not needing a companion are, I think, responses to someone who thinks their turtle is lonely and needs a friend. I think they can live quite contentedly as an "only child."

Well maybe I am in La La land, but I prefer to think that they love each other. If one of the large RES died though I wouldn't get another. It's not the same thing as growing up the same size.
Painted patience