In July, the State of Origin III, a rugby match that’s one of Australia’s most fervently watched sports events, was disrupted by a chubby, bald-headed man who ran out onto the field, clad only in running shoes.

Wati Holmwood, 33, who reportedly had oiled his body to make it more difficult for security guards to catch him, eventually was subdued, covered with blankets and escorted from the field, but not before 83,000 spectators and millions of TV viewers around the world caught a brief glimpse of a few parts of Holmwood that were better left to the imagination.

The next day, bizarrely, the father of two was at a loss to explain why he’d pulled the stunt. “It all happened so quickly -- I don’t know what was going through my head,” he told a reporter for Australia’s Daily Telegraph newspaper. “I just wanted to make (the game) interesting.”

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It was yet another inscrutable moment in the history of streaking, in which participants -- either by themselves, or in groups -- sprint naked through public places. Since streaking emerged as a what seemed like a passing fad on U.S college campuses in the mid-1970s, the propriety-tweaking, attention-seeking rite has evolved into a continuing, albeit puzzling, social phenomenon.

Over the past few decades, streakers have flaunted themselves at major public events all over the world, from the 2004 Super Bowl to the runway at the 2013 Milan Men’s Fashion Week. According to news reports, they’ve also bared their posteriors at scores of less ostentatious venues, such as a local Wal-Mart and a screening of an "Alvin and the Chipmunks" movie.

Even so, social scientists struggle to explain why doffing one’s clothes in public-- despite the risk of embarrassment, disapproval and even arrest -- has such an enduring appeal to some.

“We really don’t know that much about it,” said Justin Lehmiller, a social psychologist who teaches at Harvard University. “There hasn’t been a ton of research about people who engage in streaking behavior.”

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Doffing one’s clothes in public, of course, is a practice that goes back at least to the Dionysian rites of ancient Greece, and the first documented streaker in U.S. history was George William Crump, who ran naked across the campus of what is now Washington and Lee University back in 1804.

But it wasn’t until the Watergate era that hordes of college youth— -- as the throng of more than 500 University of Maryland students who chain-danced up a local highway in 1974 -- began flaunting their privates. The unclad dashers of 40 years ago often actually were met with approval by authority figures, who were relieved that they weren’t protesting and occupying campus buildings.

“It actually was sort of a conservative act -- engaging in 1950s hijinks, as opposed to wanting to change the world,” explained Bill Kirkpatrick, a Denison University assistant professor in communication who has researched the history of streaking. “It was almost entirely white men streaking, and it was encouraged as a return to normalcy.”

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Wati Holmwood successfully streaks millions at one of Australia’s most widely watched sports events.Getty Images

There’s still a lot of streaking on college campuses, Kirkpatrick noted and it’s sometimes even condoned by administrators as a harmless way of blowing off steam, as long as students don’t venture off campus or escalate beyond merely shocking onlookers, Kirkpatrick. But it’s also evolved from a youthful group ritual to one that’s practiced by older, lone pranksters. The secret to streaking’s appeal, he theorizes, is that it’s a relatively tame form of nonconformity.

“There are very few activities that can be both disruptive and slightly edgy, and still be deemed innocuous,” Kirkpatrick said. “In a sense, streaking exploits the gap between the public onlookers’ response, which generally is, haha, isn’t that naughty, and the response that security people or police are required to make. They have no choice but to clamp down and deal with the streaker, but the sympathies of the crowd generally are going to be on the streaker’s side. There are very few activities that can provide that sort of reaction.”

Lehmiller said it’s important to note that streaking is starkly different from exhibitionism, a disorder in which people expose their bodies to non-consenting onlookers because the resulting shock and/or disgust is an erotic turn-on.

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In contrast, there’s nothing sexual about streakers, whose motivations seem to be more complex and varied. Some may be acting under the inhibition-dulling influence of alcohol or drugs, Lehmiller said, while others simply “might not have good decision-making abilities or social awareness.”

Others, he suspects, may have overly narcissistic tendencies and crave the attention that comes from disrobing in public.

Lehmiller also wonders if some streakers belong to the subset of individuals whose brain chemistry drives them to seek intense excitement.

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“There is some interesting research on sensation seekers, which has found that they have a deficiency in the receptors for certain neurotransmitters,” he said. “They require higher levels of those chemicals to achieve the same levels of pleasure that other people experience. It could be that one of the motivations for streaking is that they need that extreme activity.”

Streaking, interestingly, still retains its appeal, even in an age when nudity seems ubiquitous across the Internet and other electronic media. Lehmiller suspects that may be because streaking provides an ordinary person -- at least for a brief moment -- with the sort of attention that a movie star gets from sending out an unclad selfie on Twitpic.

“Celebrities do that because it provides them with notoriety,” he said. “But if you’re not a celebrity, there’s no guarantee anyone will see your picture. If someone desperately wants to be seen, the only way to do that is by crashing a big event. It’d be hard to get that attention another way.”