Originally Posted by onoma
I've seen a few interviews with the author of this, and one of the claims in the book is that monogamy is more unnatural for women than for men. Also, that much of a woman's sex drive is basically controlled or dampened through societal pressure.
I haven't read this book but I have done a lot of research into evolutionary psychology recently for my course. The majority (or at least a great number) of evolutionary scientists argue, for a plethora of reasons, that monogamy is in fact more unnatural for men. This is mostly based on Trivers' theory of parental investment and the later research that was inspired by it. There are a large number of studies that suggest that polygyny (a man with more than one woman), whilst still no where near the majority (monogamy) is found to occur in much larger numbers than polyandry (a woman with more than one man)- which is considered very rare. Polyandry is also incredibly rare in most other species - unless the female is the lesser investing sex when it comes to parental investment.
Obviously, it does exist. The countless people in polyandrous situations on this site prove that but, in general it is a much lower number. Although, with the relatively recent introduction of fairly reliable birth control , this could be changing as women are no longer at risk of having to put in a larger (minimal and obligatory) investment from sex. Though it's too soon for the proposed change to have occurred through evolution it could be a cognitive thing that is going against the innate trend. I don't know, this part is merely speculation.
As for sex drive being controlled by culture, I know a lot less about that but, at a guess, I'd say that (like in most circumstances) both biology and culture play a part.
I'd agree with what others have said though, if you're partner identifies as mono - leave her be. This book suggests that monogamy is unnatural for women but there are lots of books that suggest that polyamory is general in unnatural. It doesn't mean it's true and if there's one thing people don't like, it's being told that the way they are is wrong or unnatural. I appreciate that you probably weren't trying to do that and probably were just introducing them to a book with an interesting perspective, but if they're happy as they are don't try and push them.