Many would be surprised to learn that either head had any personality, and yet…
Janus — despite the single name given — seems to be a set of conjoined tortoise twins. (Here’s a human example.) The handlers acknowledge that survival in the wild would be unlikely. For one thing, both heads can’t retract into the shell.
So it’s not surprising that the two heads would have different personalities — except insofar as a tortoise or turtle has any personality at all. And it turns out that they are smarter than we used to think.
For example, researchers have shown that some can learn.
Takehome: Researchers have found that tortoises are really slow but smarter than we thought. However, their neuroscience differs from ours. There is no tree of intelligence.
You may also wish to read: Do ants think? Yes, they do — but they think like computers. Computer programmers have adapted some ant problem-solving methods to software programs (but without the need for complex chemical scents). Navigation expert Eric Cassell points out that algorithms have made the ant one of the most successful insects ever, both in numbers and complexity.