The committed partnership between a man and a woman evolved, some say, for the well-being of children.
"The human species has evolved to make commitments between males and females in regards to raising their offspring, so this is a bond," said Jane Lancaster.
"I don't think we are a monogamous animal," said Pepper Schwartz, "A really monogamous animal is a goose – which never mates again even if its mate is killed ... Monogamy is invented for order and investment – but not necessarily because it's 'natural.'"
Storyteller: Jane Lancaster, evolutionary anthropologist, University of New Mexico.
Storyteller: Professor of sociology at the University of Washington in Seattle.
Are Humans Meant to be Monogamous?