Men, higher earners and those who work longer hours - which researchers say can signify a position of power - in straight couples tend to do the yard work and outdoor, auto and more traditionally male chores that tend to be less time-consuming.
Yet in same-sex couples, income and work hours didn't have the same affect. And, perhaps most important, same-sex couples were much more likely to share equally the time-consuming work of routine child care - 74 per cent of gay couples versus 38 per cent of straight couples. And gay couples were more likely to equally share the unpredictable work of caring for a sick child - 62 per cent versus 32 per cent for straight couples.
Why is that important? In straight couples, women are still often considered the primary, or default, parent, responsible not only for organising, overseeing and caring for children but for also doing many of household chores. Time diary data shows that women, even when they work full-time, tend to spend about twice as much time doing housework and caring for children.
"There's been a lot of calls for more sharing of child care responsibilities, so it isn't only a woman's problem and she isn't the only one dealing with the fallout at work. But we see more sharing in same-sex couples," said Ken Matos, FWI senior director of research and author of the study.
"Taking on primary child care responsibility impacts one's work time. It creates so many unscheduled interruptions, so that's an important thing to be shared."
The survey also found that men in same-sex relationships were more satisfied with the division of labor than were women in straight relationships. The reason? Same-sex couples talked about it more.
Men in gay partnerships were much more likely to say they had discussed how to divide the labor when they first moved in together. Women in straight partnerships were much more likely to say they wanted to, but didn't.
"The people who said they bit their tongue had a lower satisfaction with division of household responsibilities," Matos said.
"So satisfaction may not be so much about what you do, but whether or not you felt you had a voice. Did you say what you wanted? Or did you let it evolve and feel like you couldn't pull yourself out of the situation once it settled and got stuck?"
In the survey, 20 per cent of women in straight couples said they hadn't spoken up about how to divide the labor fairly but wish they had. In same-sex couples, 15 per cent of the women had.
"Perhaps because they can't default to gender, people in same-sex couples are in more of a position to have these conversations," Matos said.
"That's probably the biggest takeaway of the survey: how important it is to talk and say what you want, rather than stay silent, not wanting to start a fight, making assumptions, and then letting things fester."