The author is surely correct to point out that in modern cultures, strict monogamy is minimally practiced. Deviations include extra-marital affairs and serial monogamy, that is, divorce and remarriage. Based on this reality, the author actually advocates for responsible non-monogamy, or polyamory, which involves a wide range of sexual relationships involving at least three individuals in the same period of time.
The author assures the reader that polyamory is not the equivalent of "swinging," but the differences seem to be negligible. She suggests "coming out" and joining polyamory groups, the sole purpose of which is to gain intimate partners. However, generally, loving relationships are not dependent on being formed in groups where sex is obviously foremost.
To the author, polyamory is an honest approach to life. Negative emotions like jealously have to be overcome. And there is some truth to that. But she downplays the realities of life in maintaining even one relationship. For those who work fulltime with countless family responsibilities including the raising of children, the demands of establishing and maintaining a second relationship without severely impacting the first would be daunting to say the least. Furthermore, it is asking a lot of the other partner to accept extra-marital relationships regardless of any attempts at honesty. The difficulties go way beyond jealousy. It is no wonder that in the interests of self- and marital-preservation that most affairs are kept discreet.
It is difficult to see where the concept of polyamory has a whole lot of validity for the general population. A general life-style of polyamory would seem to appeal to those with strong sexual proclivities, with few real-world, time-consuming commitments. Needless to say, this book is not going to be the basis of a surge of uninhibited, multi-partnered individuals. Most people are just not that obsessed with sex.