Do you think most people designed for monogamy or polygamy?

its well known- women are more emotional and can be with one sex partner their whole life but men are less emotional and can have multiple sex partners their whole life. From family and friends I see that most women and men are either divorced, single, or cheating. Then very few people I know are married living happily ever after. I actually only two people like that- both co workers but they could be swingers for all i know. Does anyone know the divorce rate in the world? Where could I find statistics on how many people actually have one sex partner their whole life? Do you think most people designed for monogamy or polygamy?