As revealed by numerous true hormonal experts online (and in books on this subject), the vast majority of "facts" cited by this author simply are wrong. In many cases are OPPOSITE what the real life actual case is! Especially in anything discussing oxytocin!
It is a shame that an author like this (who IMO is a terrible relationship guru in general... please see relationship related books by Paul Pearsall) would write up a book where his "expertise" is absolute ignorance and people, not knowing better, read it and accept at face value.
And then give it good ratings as they don't know any better!
There are some very good books out there on oxytocin (The Moral Molecule, The Oxytocin Factor, The Chemical of Connection, etcetera) plus some VG information online that have REAL (true) info on oxytocin... please read those.
For relationship problems, read Love Sense by Dr. Sue Johnson, the relationship books by Dr. Hugh Prather, the relationship books by Dr. Paul Pearsall and stay away from fake "self help gurus" like Gray (who has himself been married how many times now?).
IMO, the (supposed) Self Help Movement in this country has done serious harm with little - if any - help than most people imagine (a point emphasized by Dr. Pearsall in his - only partly relationship oriented - book "The Last Self Help Book That You'll Ever Need"