Same sex marriage is the legal union of two persons of the same gender.
As 29 out of 195 countries across the world have legalized same sex marriage, it shows that the attitudes and opinions have changed dramatically over the years. Numerous polls and studies on the issue have been conducted over the past few decades, and a consistent trend of increasing support for same-sex marriage has been revealed, often driven in large part by a significant generational gap. Support for legal same-sex marriage has increased across every age group, political ideology, religion, gender, race and region of various developed countries in the world. The Center for Global Development released a new study that finds that just as social attitudes toward gays and lesbians have changed rapidly in the developed world, these attitudes are also changing in the developing world. The study also suggests that the changes in social attitudes often follow and are caused by changes in government policy toward gays and lesbians.
According to the Pew Research Center, as support for the recognition of same-sex marriage in all developed democracies and in some developing democracies has continually risen, in the US it has leveled out more recently. As of 2019, the majority of Americans (61%) favor allowing gays and lesbians to marry legally, while about half as many (31%) oppose same-sex marriage. This is in stark contrast to the opinion in 2004 where 60% opposed same-sex marriage, while just 31% were in favor.
The biggest opponents of same sex marriage are religious fundamental groups. For conservative Christians, the belief that marriage exists for procreation means that homosexual unions are unnatural. Secular social conservatives tend to agree that marriage is between a man and a woman -- societies privilege heterosexual marriage principally because it creates enduring mother-father child-raising units. Homosexual marriages, whatever their advantages, do not serve this purposes. However many studies show that children of same-sex couples manage just as well as children of opposite-sex couples, with some studies showing benefits of being raised by same-sex couples.