Vasopressin—a neurochemical in males—facilitates bonding with one female partner and with the offspring of that female. Having multiple sexual partners and viewing pornography short-circuits the function of vasopressin and damages the ability of males to bond (Sean McDowell, "Why Evolutionary Theory Is Wrong About Sex," Conversantlife.com, April 29, 2009).

The Ten Commandments condemn promiscuity, and the ideal marriage in the Bible is between one man and one woman for life. Other relationship structures, as King Solomon realized after his experience, lead to trouble.