On a routine tram ride into work this morning, a mother with a double pram tries to squeeze past suit-clad commuters with their heads buried in smartphones. She has no luck.

A man in his 40s sits comfortably sprawled across two seats and takes no notice of her — and she is now exasperated.

This man is guilty of "manspreading", a term used to describe the habit some men exhibit of selfishly taking up more space on public transportation than they need. This includes opening their legs and impinging on adjacent seats, and sometimes taking up two or more seats.

The behaviour is frequently called out by angry social media users, who argue men should be more considerate of women travellers.

But a new study has found that, far from being a turn-off, some people find manspreading an attractive trait.

Manspreading in action

The problem is so pervasive that manspreading is considered a crime in busy New York City.

Yes, a report on the New York Police Department's attitudes towards race and class last year revealed two men were arrested for "manspreading" on the subway, "presumably because they were taking up more than one seat and therefore inconveniencing other riders".

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But manspreading is also an issue in Australia, with frustrated commuters regularly documenting their experiences with the phenomenon on crowded trains, trams and buses.

"This guy was heaps mad he couldn't have this 3-seater to himself," one Sydney commuter posted on Instagram last week.

Another recently tweeted: "Man sits right next to me with his huge bag and newspaper and proceeds to occupy most of the seat. Douche. #sydneytrains".

There is also a Facebook group dedicated to "outing" manspreaders, where members post pictures of and poke fun at those who are encroaching on the personal space of others on public transport.

Spread the love, study finds

For some commuters, however, manspreading might not arouse anger so much as romantic interest.

A new study published this week in Proceedings of the National Academy of Sciences found men and women who adopted "expansive postures" in speed dating scenarios were deemed more attractive by members of the opposite sex.

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For the two-part study, Tanya Vacharkulksemsuk, a post-doctoral research fellow at the University of California, Berkeley, and her research team used video footage from a speed-dating event that showed men and women who exhibited more expansive body language - for example, outstretched limbs - were more likely to get follow-up dates.

The researchers also observed this trend online. Dating app users whose profile pictures showed them in open, dominant poses - like leaning back with legs outstretched, or standing with their arms out wide - were more likely to generate interest from other users, though this strategy worked more effectively for men than women.

Don't get too comfortable...

So if you're sexy and you know it, should you manspread? Not necessarily, says Australian body language expert, David Alssema.

Alessma told ABC News he agrees, in part, with the study's findings, but warned not everyone would find the "alpha male" behaviour attractive.

"Manspreaders are known to be confident. Confident people take up more space in a room. If you see a popular person on the couch they are in usually in the middle - arms out, legs spread. They are trying to show their persona of confidence and lot of people see confidence as a winning quality," Mr Alessma said.

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"A lot of men may also use [manspreading behaviour] to attract attention from the opposite sex, which is why they spread their legs and put their hands around their belt region."

Sydney University Professor of Gender and Cultural Studies Elspeth Probyn said she sees plenty of "manspreading" in her lecture halls.

"I particularly have noticed men in class who sit fully open, leaning back and that is a position of power," Professor Probyn told ABC News.

"In this context it's about a female professor lecturing them. There are so many gendered issues around this stuff in different environments."

Professor Probyn believes dominant body language might be attractive to some women but said it was "very annoying in public spaces where there is no context of dating".

"It can be about power - the ability to control space is really important and people would say, 'Oh you are overreacting, its not power'. But the ability to take up someone else's space is essentially about power."

Making anti-social behaviour illegal

In January 2015, New York's Metropolitan Transportation Authority launched a public transport etiquette campaign to curb manspreading, which included a poster of a male figure spreading his legs and the quote: "Dude ... Stop the spread, please. It's a space issue."

A campaign launched by New York City's Metropolitan Transport Authority in January 2015 urges men to 'stop the spread'. ( Supplied: Metropolitan Transport Authority )

Bus and subway officials were also given the power to arrest passengers for the offence of "manspreading".

Meanwhile, authorities in San Francisco are looking at introducing fines of up to $500 to stop the scourge of "manspreading" on BART trains.

However, a Sydney Trains spokesperson told ABC News it had no plans to fine passengers for manspreading.

"Sydney Trains encourages customers to show courtesy for others. This includes not taking up more room than necessary ... station and train staff regularly make announcements to remind customers to consider others when catching a train," the spokesperson said.

What's a girl to do?

Certainly women are drawn to men with confidence, and confidence is [apparently] sometimes expressed via a manspread. And of course, public transport and discomfort go together - simply inevitable bedfellows.

But in the context of this morning's tram ride, there was nothing attractive about a man whose entitled behaviour showed little regard for others. No doubt the woman with the pram agrees.

In the meantime, perhaps women can take a cue from writer Cassie J Sneider. While many feel frustrated that they have to ask men to move, Sneider resorts to the more drastic measure of sitting on men who take up too much space on the train.

Now that's one way to quash a problem.