Final answer:
Monogamy is sociologically and environmentally favorable as it facilitates mobility, stability, and a suitable platform for raising offspring. It is common in postindustrial societies while polygamy is often related to economic needs in agricultural societies. Legal aspects, like those in same-sex marriage, highlight the significance of social and financial benefits of monogamy.
Step-by-step explanation:
The sociological and environmental factors that make monogamy favorable include its adaptation to highly mobile societies and cultures, such as those of postindustrial societies or nomadic foragers. Monogamous unions produce smaller family units which can navigate such environments more easily. Sociologically, monogamy provides a framework for long-term socioeconomic stability with shared labor and resources, reducing competition for mates and creating stable family units for raising offspring. Environmental factors in monogamy are observed in animals like birds and wolves, where it can lead to better protection and rearing of young by males, as described by the "male-assistance hypothesis". Socially, laws like those established through Obergefell v. Hodges and studies of cultures with both monogamous and polygamous systems, like those in the Central African Republic and Cameroon, show varying preferences for monogamy based on economic and social stress factors.
Polygamy, while less common in postindustrial nations, can be a strategy employed in societies with high mortality rates or skewed population distributions. It is also noted that in cultures with small-scale farming, polygamy can bring economic advantages by producing more children to assist with agricultural labor. Conversely, the legalization of same-sex marriage in 30 countries, including the U.S., underscores the importance of social and financial benefits associated with legal recognition of marriage, such as Social Security benefits and medical insurance.