"develop biases" is anthropomorphism. It's like saying "Fable there are two programming languages, mimblewort and bafflewick, which do you choose?"
The results show 51% mimblewort / 49% bafflewick. Fable based it on nothing! I've demonstrated Fable has bias and is unsuited for use in software engineering.
Actually... if that happened (with a delta outside the margin for error/randomness), you did demonstrate a bias!
That's the point - those two made-up things should have resulted in an equal split. If it didn't, then Fable is using something in its training data to lean towards one of them (once again, note that the scientist conducting the trial would have set a P-value before starting).