Sexy selfies are on the rise and it's because of income inequality, scientists say.

The latest research suggests women are more likely to share racy pictures on social networks when they're paid less than men in order to 'increase their status'.

Sexual attractiveness can generate large returns economically, socially, and personally. As a result, the trend seen in the latest research makes a lot of sense from an evolutionary point of view, scientists said.

Until now, researchers believed the trend of sharing sexualised images would increase in areas with greater gender inequality and female disempowerment.

However, the research found income inequality was most frequently associated with the number of sexualised images posted by women online.

For the latest study, researchers analysed tens of thousands of selfies posted to Instagram and Twitter across 113 countries.

Scroll down for video

New research suggests women are more likely to share racy pictures when they're paid less than men in order to 'increase their status' (stock image)

Scientists from the University of New South Wales found that women who live in environments with greater economic inequality were the most likely to sexualise themselves in images.

Lead author Dr. Khandis Blake from UNSW Science's School of Biological, Earth and Environmental Sciences said her team tracked posts where women had taken selfies and then noted whether they had added social hashtags using words like 'sexy', 'hot', or similar terms.

'We then looked at where in the world these things happened most,' Dr Blake said.

'The number one way that psychologists usually look at women's preoccupation with their appearance is that it happens because of patriarchal pressures – that women live in societies that value their appearance more than their other qualities.

'The argument is usually that when you see sexualisation, you see disempowerment', she said.

Instead, researchers found women are more likely to invest time and effort into posting sexy selfies online not necessarily in places of disempowerment, but in those where economic inequality is rising.

'Sexualisation manifests in response to economic conditions but does not covary with female subordination,' the research paper notes.

The findings, published in the journal Proceedings of the National Academy of Sciences, are consistent across different geographic locations.

This is even after taking into account and controlling for other factors that could influence patterns, like population size, human development, and internet access.

Researchers say income inequality increases competitiveness and status anxiety among people at all levels of the social hierarchy.

This makes them sensitive to where they sit on the social ladder and also makes them want to do better than others.

'That income inequality is a big predictor of sexy selfies suggests that sexy selfies are a marker of social climbing among women that tracks economic incentives in the local environment,' Dr. Blake said.

Researchers came to the conclusion after analysing tens of thousands of social media posts from across 113 countries (stock image)

Which job has the smallest pay gap? The job with the smallest gap in wages between men and women is train driving, it has been claimed. The gender pay gap for train drivers is just 0.7 per cent, according to the drivers' union Aslef. Officials said they have strong collective bargaining agreements with rail companies, which have helped keep any wage differences down. General secretary Mick Whelan said: 'Train drivers are highly unionised and covered and protected by strong collective bargaining agreements - factors which have helped deliver this success story. 'However, while this news is welcome, we know the rail industry needs to do more to improve its recruitment policies and we will work with the train operators to make sure this happens.' Aslef has 19,661 members, 6.5 per cent of whom are women. Advertisement

'Rightly or wrongly, in today's environment, looking sexy can generate large returns, economically, socially, and personally.'

The researchers found the exact same pattern in real-world spending in other appearance-enhancing areas.

'What we found in more than 1,000 different economic areas in the US when looking at women's spending in beauty salons and clothing stores is that income inequality is also predicting this type of spending,' Dr. Blake said.

The researchers say the findings makes sense from an evolutionary point of view.

'In evolutionary terms, these kinds of behaviours are completely rational, even adaptive.

'The basic idea is that the way people compete for mates, and the things they do to put themselves at the top of the hierarchy are really important,' Dr Blake said.

'This is where this research fits in – it's all about how women are competing and why they're competing.

'So, when a young woman adjusts her bikini provocatively with her phone at the ready, don't think of her as vacuous or as a victim.

'Think of her as a strategic player in a complex social and evolutionary game. She's out to maximise her lot in life, just like everyone,' she said.