Girl Maths – a mindset justifying people to spend more than they can afford

Girl Maths – a mindset justifying people to spend more than they can afford

Experts from RMIT University are available talk to media about the TikTok phenomenon ‘Girl Maths’ and why it’s not doing girls any financial or social favours.

Dr Janneke Blijlevens, Senior Lecturer in Marketing

Topics:  Girl Maths, consumer behaviour, decision-making, behavioural biases and heuristics, behavioural business, money behaviours  

“Girl Maths – currently trending on social media – is providing us with the unique opportunity to see behavioural biases and heuristics play out in real life.  

“Marketing tactics have now become so ingrained in consumers that they don’t even need messaging to ‘help’ them justify their purchase decisions anymore. They can do it all on their own.  

“Behavioural biases and heuristics are shortcuts in our thinking that help us make decisions quicker and easier.  

“Our brain has a lot of decisions to make in a day and simply doesn’t have the energy and power to scrutinise every little detail of every decision.  

“These shortcuts in our thinking facilitate the decision-making process. Unfortunately, these shortcuts, or biases, are not always helpful in making the best decisions for ourselves.

“Girl Maths is a perfect display of cognitive dissonance, confirmation bias, mental accounting being applied to consumption decisions.

“It all starts with cognitive dissonance. You want the dress, but you know that financially you can’t justify it. So to get rid of that dissonance – the space between what you want and what you should do – you apply biases and heuristics (or shortcuts) to your thinking to make that go away.

“Confirmation bias is a bias where you justify your decisions by considering only the evidence that supports what you want and ignore the evidence that would mean you’d have to make a different decision.  

“You justify buying the dress because you have several events coming up, which means you’ll wear that dress at least four times and won’t have to buy dresses for those other occasions. And we all know considering cost-per-wear is being financially literate and savvy.

“However, you are ignoring the fact that 1) your bank account is still going to show a deficit if your disposable income does not match this expense, 2) you could re-wear a cheaper dress all the same, and 3) your power and gas bills will have gone up by the time you wear it for a third time.”

Dr Janneke (“Yah-nuh-kah”) Blijlevens is a member of the RMIT Behavioural Business Lab and Consumer Wellbeing Research Group. With expertise in consumer decision-making and behaviour change, she frequently comments on decision paralysis, choice overload, marketing tactics used to influence consumer decision-making, the psychology behind purchase decisions, and how to design behavioural interventions to help people make better decisions for their own wellbeing.    


Dr Angel Zhong, Associate Professor of Finance

Topics: investor behaviour, financial literacy, financial wellbeing, retail investors, finfluencers 

“The Girl Maths trend highlights the impact of ‘finfluencers’, whereby financial information consumed online influence investment decisions.  

“Young consumers and inexperienced investors are more susceptible to the impact of finfluencers .  

“Girl Maths disregards the opportunity cost and the time value of the money spent.

“While it seems so much cheaper when you spread the cost of a high-end dress over a number of years to bring it down, you tend to forget the fact that inflation erodes purchasing power of your money.  

“Also, by spending money on a fancy dress, you lose the opportunity to spend the money on better investments for wealth accumulation.

“Girl Maths is similar to buy-now-pay-later. This mindset encourages people to spend more than they can afford.”

Dr Angel Zhong is a finance academic who specialises in empirical asset pricing, digital finance, global financial markets, investor behaviour and the recent trends in retail investing.    


Dr Lauren Gurrieri, Associate Professor of Marketing 

Topics: gender and marketing, gender and consumption, influencer marketing 

“The term ‘Girl Maths’ reinforces problematic stereotypes that equate women with consumption, frivolity and extravagant spending.  

“Rather than a logic that speaks to purchase justification and cost-per-use, the term is unnecessarily gendered.

“The use of ‘girl’ as opposed to ‘woman’ also signifies sexist language.  

“It implies someone is child-like or lacking in knowledge or experience. Accordingly, the term operates to both demean and exclude on a gendered basis.

“This highlights the challenges of content creators going viral and reaching large audiences with problematic trends, in this case, promoting stereotypes that stymie gender equality.”

Dr Lauren Gurrieri is an Associate Professor of Marketing at RMIT University and the Co-Director of the Centre for Organisations and Social Change. Her research examines gender, consumption and the marketplace, with a focus on inequalities and harms (re)produced and experienced across consumer and digital cultures.  

aboriginal flag
torres strait flag

Acknowledgement of Country

RMIT University acknowledges the people of the Woi wurrung and Boon wurrung language groups of the eastern Kulin Nation on whose unceded lands we conduct the business of the University. RMIT University respectfully acknowledges their Ancestors and Elders, past and present. RMIT also acknowledges the Traditional Custodians and their Ancestors of the lands and waters across Australia where we conduct our business - Artwork 'Luwaytini' by Mark Cleaver, Palawa.