A study conducted in the US found that both gay and straight political canvassers influenced people’s opinions on marriage equality – however, only those who spoke to gay canvassers had their opinions changed for a longer period of time.

Researchers Michael LaCour of UCLA and Donald Green of Columbia University found that both gay and straight canvassers had a positive effect on recipients during 20-minute pro-marriage equality conversations. Yet, only gay canvassers had effects that “persisted in three-week, six-week and nine-month follow-ups.”

ScienceMag‘s editor summary says: “LaCour and Green demonstrate that simply a 20-minute conversation with a gay canvasser produced a large and sustained shift in attitudes toward same-sex marriage for Los Angeles County residents.”

In a second similar study, research found that gay canvassers sustained political change on the subject of gay rights and gave “strong evidence of within-household transmission of opinion change, but only in the wake of conversations with gay canvassers. Contact with gay canvassers further caused substantial change in the ratings of gay men and lesbians more generally.”

New York magazine notes the theory of ‘contact hypothesis‘ whereby contact with someone from a different ethnicity, background, race, sexuality group can make you sympathetic to that person’s cause.

New York magazine suggests that “those personal stories the gay canvassers told appear to have had a bigger impact than the stories straight canvassers told about friends or family members.”

In the abstract, the researchers concluded that “[…] contact with minorities coupled with discussion of issues pertinent to them is capable of producing a cascade of opinion change.”