I don&#039;t buy it. If, by &quot;not natural&quot; you mean not existing in nature, both of those throwaway phrases illogically mashed together are not correct, because both DO occur in nature. However, in an ordered society, monogamy as the ideal has helped societies survive and thrive by providing (again, the ideal toward which to strive) a stable family unit. But back to the great pains to make monogamy and nonmanogamy biologically equivalent: not so, as the brain produces and releases a hormone (oxytocin) that leads to bonding between sexual partners. Very rarely is sex really &quot;just sex.&quot;