Today is Go Topless Day, where women across America take off their shirts to support gender equality and to celebrate — or, in places where it’s still illegal, to protest for — the right to walk around topless just like men can, while men show solidarity by wearing bras or bikini tops. Since the event was first organized in 2008, participants have taken to the streets in more than 40 cities across the United States and around the world.

As one Go Topless Day organizer put it in a 2011 interview, “This is not a beauty contest. It is about freedom.” The big idea behind Go Topless Day — well, the big idea that has nothing to do with aliens, but we’ll get back to that — is that there’s nothing more inherently sexual about women’s breasts than men’s, and that one good way to break down societal attitudes about sex and nudity is to make it unremarkable to see women walking around topless.

There’s some science to back up that idea. A 1994 study out of Australia — easily the chillest outpost of the former British Empire, admittedly — asked 116 female psychology students about their experiences with toplessness. About half the participants had been to a topless beach, and the researchers found that “Those who had ever gone topless were less likely to believe that going topless was sexual, had more permissive sexual attitudes, attended church less often, had a more favorable attitude to going topless, believed that the community approved of topless behavior, believed that significant others were approving of topless behavior, and had higher self-esteem and higher body attitudes.”

There’s a lot there, and it’s always tricky to guess what behavior actually causes another when dealing with studies like this. (And 116 Australian college students are hardly representative of everyone.) But the correlation between being topless, seeing toplessness as non-sexual, believing the community approves of toplessness, and having more positive body attitudes overall is an intriguing one. Whether the experience of going to a topless beach causes such a shift in attitudes, or if it’s just a good outlet for women who hold these beliefs in the first place, the study still suggests there are good reasons to support public toplessness, and none of them have to do with sex.

As for the day itself, it’s worth noting that Go Topless Day has some rather unusual roots. As you might be able to see in the fine print on the poster up top, the day is sponsored by the Raëlian movement, a UFO religion founded by a French racing journalist after a claimed encounter in 1973 with humanity’s alien creators. Raëlism calls for absolute gender equality, hence the creation of Go Topless Day. It’s hard to say quite where the Raëlian publicity stunt ends and the sincere declaration of equality begins, but since it’s quite easy to support a woman’s right to be topless in public if she so chooses without believing anything in particular about UFOs — especially when there’s plenty of good science to back up the former, and distinctly less good science to back up the latter — this probably isn’t that much of a problem.

Photos via Getty Images / Kena Betancur