For the entire 500,000 years that humans have lived in villages (groups characterized by a "way of life" defined by roles), the (sexual) coupling of a male with a female has been understood to be a vitally important part of the "way of life" of the village.

Over the entire sequence of 25,000 successive families that succeeded at the game of life in order to produce you, people understood from both experience and tradition that copulation results in a powerful and enduring bond between the male and female.

Such couples had an evolutionary advantage in producing offspring who would themselves be successful as parents. There was a time when archaeologists thought that our ancestors evolved from lone hunters to male/female couples and then to mixed sex groups with undifferentiated roles and then to what are here called villages. [See] In that Tarzan/Jane view of our past, survival of the female would simply not have been possible in the absence of a strong emotional bond and strong provider/protector instincts in the male.

If, instead, our ancestors evolved from lone hunters directly to mixed sex groups with undifferentiated roles and then to villages with gender and other roles, the development of gender specialization could not have proceeded without such bonds and instincts. In that scenario, there would still be the formation of couples bonding together, but in addition, the males collectively in the group would have bonded together as providers and protectors of their village, and the females would have bonded together as nurturers of their village and for food gathering and preparation.

As groups evolved to exhibit gender and other role specialization, those groups that developed such emotional bonds and instincts would have an advantage in the competition with other groups (and with other species) for scarce game and water. Finally, as the innovation of moral rules emerged, the "way of life" of a village became manifest not only in gender and other roles, but also in moral and other rules of behavior.

As such "ways of life" developed, they came to include symbols and rituals which expressed the gender roles and rules applicable to the male/female (sexual) couple, and thus the concept of "marriage" emerged.