Robinson advocates that couples should make love without orgasm for a period in order to break a cycle of neurochemical peaks and valleys. She says hot sex produces dopamine rushes followed by a sense of depletion as dopamine levels return to normal. At the same time, a normal rise in the level of prolactin turns the attention away from sex.
Robinson says that this feeling of depletion can be projected onto the sex partner and experienced as the desire to withdraw and find a new partner.
... dopamine drives you to have sex over most other activities. With dopamine as the driving force, biology has designed you to engage in fertilization behavior to make more babies, and urges you to move on to new partners to create greater genetic variety among your offspring. Your primitive brain accomplishes these goals of more progeny and promiscuity by manipulating your brain chemistry, and thus your desires and thoughts. High levels of dopamine increase sexual desire, encouraging you to behave recklessly.
However, humans are among the estimated 3 percent of mammals whose brains are hard-wired for monogamy. Unlike most mammals, our reward centers are also rich in oxytocin receptors. When we make love, and especially when we orgasm, the release of oxytocin stimulates the reward center to not only associate sex with pleasure, but also to associate that specific other with the source of that pleasure, creating the bond we call "true love."
High levels of oxytocin along with that addictive dopamine associated with sex cause us to behave monogamously.
There seems to be another flaw in Robinson's argument: She says couples should focus their lovemaking on activities that increase oxytocin levels, rather than those that increase dopamine levels; therefore, no orgasms. But orgasm itself floods the body with oxytocin.
I think the idea of working to understand and improve relationships on the neurochemical level is brilliant, and I have no doubt Robinson's system can improve lovers' union. But I think her explanations of the science behind her ideas is off.