By Nick Collins, Science Correspondent 8:00PM BST 20 May 2012
Early humans became monogomous because women evolved to prefer reliable providers over macho alpha males, a study has found.
While physically imposing men hold a certain appeal, women long ago evolved to value qualities like loyalty and generosity over bulging muscles and a strong jawline.
This is because men who lacked the ability to compete physically with their peers compensated by providing better for their spouses in order to buy their affection, researchers said.
The rise of the Beta male began at an early stage of human evolution when our ancestors lived in large social groups where the most dominant men had access to the most women.
Lower-ranking men had to develop another strategy for obtaining a mate, and did so by devoting themselves to one woman and providing her with all the food and protection she needed.
This led women to value a generous and devoted partner over a promiscuous stronger man, laying the first foundations for monogamous family life, researchers from Tennessee university said.