Here`s why same-sex marriage is usually opposed

With the idea of same sex marriage still being unacceptable for a large section of the population, a new study has pointed to self-interest as a leading cause.

The UCLA psychology study concluded that many people believe gay men and women are more sexually promiscuous than heterosexuals, which they may fear could threaten their own marriages and their way of life.

Lead author David Pinsof said that many people who oppose same-sex marriage are uncomfortable with casual sex and feel threatened by sexual promiscuity.

Such people often marry at a younger age, have more children and believe in traditional gender roles in which men are the breadwinners and women are housewives.

Pinsof noted that sexual promiscuity may be threatening to these people because it provides more temptations for spouses to cheat on one another. On the other hand, for people who are comfortable with women being more economically independent, marrying at a later age and having more sexual partners, sexual promiscuity is not as much of a threat because women do not depend on men for financial support. The researchers measured people's attitudes, regardless of their accuracy.

People who feel their way of life is most threatened by sexual promiscuity tend to be socially conservative and strongly believe in traditional gender roles. Among them are women who prioritize family over career and who view their marital vows as sacred, said senior author Martie Haselton.

The researchers surveyed 523 men and 562 women, 27 percent of whom oppose same-sex marriage.

The study appears online in the journal Psychological Science.