Study: Anti-gay bias diminished across U.S. after same-sex legislation

MONTREAL — The legalization of same-sex marriage in the U.S. has had a significant impact in lessening anti-gay bias in many areas across the country, a recent study shows.

Researchers from McGill University say the findings are evidence that public policy can influence social norms and individuals’ attitudes.

“The idea that norms shape attitudes has been around in social psychology for many years,” said Eric Hehman, senior author of the study and a professor of psychology at McGill University in Montreal. “We wanted to measure if laws and policies can also act as norms and potentially change deeply rooted biases.”

Hehman and his team were able to map trends in anti-gay bias using polling data focused on different areas of the country over a period of 11 years, between 2004 — when Massachusetts was the first of 34 states to legalize same-sex marriage — and 2015, when the Supreme Court ruled that gay couples could marry anywhere in the country.

The researchers found that implicit and explicit anti-gay bias was decreasing or stable in most areas of the country before full same-sex marriage legalization, but after local legislation passed in support of same-sex marriage, the reduction in anti-gay bias nearly doubled.

In the 15 states that didn’t pass same-sex marriage legalization bills, the researchers found backlash against the gay community following the SCOTUS ruling. Anti-gay bias increased in these places.

“In other words, representative governments can contribute to and/or intensify change in the attitude of citizens by passing legislation,” says Hehman. “We have some evidence that the laws caused this changed in bias, but it is possible the effect goes in both directions.”

Public opinion polls since 2015 have shown that national support for gay marriage has increased.

The study is published in the journal PNAS.