It has long been a subject of fascination that two girls created such a rich and layered, even provocative, fantasy world. It is even more fascinating to consider that they both were able to inhabit this make-believe world so completely, that their fantasies were so deeply shared.
At the time of their trial, defense attorneys suggested that the pair were suffering from a "folie des deux," a kind of shared insanity, through which the girls, described by their defense attorneys as elated paranoiacs, were able to communicate and share the most minute details of their fantasies. It was a world that was open only to the two of them, and in that world, they were even more special than they themselves, in their most grandiose egoism had previously imagined.
As Parker wrote in her diary not long after their first shared excursion to the imaginary Fourth World: "We now know that we know are not genii (Parker's approximation of the plural for "genius") as we thought. We have an extra part of our brain which can appreciate the fourth world."
But there are others who suggest that the Fourth World was the only place where two young girls of such widely different social pedigrees could have found common ground in the rigid, post Victorian class-conscious city of Christchurch.