Morality

What is morality? Is morality part of human DNA? Or is morality simply humans being conditioned to live in a certain type of societal setting? After three years in an Arab Muslim social setting, polygamy is no more an issue of morality in my mind. I know and have met educated, beautiful, successful, modern Arab women, who out of choosing and even love, are second or third wives. They are not ashamed and there is no stigmata attached. They show no sign of subjugation, exploitation or denigration of the woman, that is attached to the moral stand on polygamy.