Reading this book is all about suspension of disbelief. All fiction requires some suspension of disbelief as it is, after all, fiction. But this book requires far more than it should.
I can contrast this with another book I read, Bloodsucking Fiends. BloodSucking Fiends is of course about vampires, and to read the book you have to suspend your disbelief in vampires. But once you have done so, the rest of the book makes perfect sense. A person is turned into a vampire and behaves as you would expect someone to behave under those circumstances. Someone finds out a friend is a vampire and their reaction is logical and believable. The only unrealistic bit is the vampires themselves. No problem.
The Woman and the Ape on the other hand inspires disbelief at every turn. In fact the Super Intelligent Talking Ape (who turns out to be not an ape at all, though none of the so called "PhDs in Zooology that the book abounds with actually seems to notice this) is the most believable character in it. Actually just a hairy, longarmed, race of human, he has his own agenda, and comes from a separate culture and so his actions, when strange, are explainable away.
The rest of the characters are meant to be normal, if upper class, English and Danish europeans. But they act less like any Englishman I've met than the ape does. Are we honestly expected to believe that these characters are supposed to be sane humans?
It is terribly annoying to try to read a book about characters who are supposed to be normal people, and yet each action or conversation they do is totally unpredictable. This was also one of my complaints about Oscar and Lucinda.
To give an example from literature, look at Alice in Wonderland. When we have talking March Hares and Playing cards, their behaviour can be off the wall, because we have no pre-existing standards for them, but Alice is supposed to, and does, behave like a confused and scared little girl. It all works out.
In this book we have all sorts of normal people doing things that make no sense whatsoever, and yet part of the plot is that these are normal people. Eventually the entire population of Britain starts behaving in a manner with no precendent whatsoever.
The only excuse the author has is that he is Danish and presumably was writing for Danes. To a Dane the English are not as familiar as they are to me, and so more outlandish behaviour might be believable. Except of course that Denmark is right next to England and they would meet Poms all the time. This excuse might hold some water if the book was writen in Korea or somewhere.
If you must: The Woman and the Ape