What’s the secret to being confident? Some people believe it’s having a positive mental attitude, while others claim it’s being wealthy.

But according to one researcher, the answer may in fact lie in what we’re wearing.

Professor Karen Pine from the University of Hertfordshire said that specific clothing – including even superhero T-shirts – can make people more confident in all sorts of situations.

The research is outlined in her new book Mind What You Wear.

In the book she claims clothing affects a person’s mental processes and perceptions.

And ultimately, what you wear could discern how confident you feel about yourself.

‘Now research shows what we wear affects us too.

‘Putting on different clothes creates different thoughts and mental processes.

In the study, she gathered a group of students and asked some to wear a superman T-shirt.

She wanted to know if heroic clothing would change how students thought.

Surprisingly, she found that not only did it make them more confident, but it also made them actually think they were physically stronger.

‘When wearing a Superman T-shirt the students rated themselves as more likeable and superior to other students,’ she explained in a release from the University of Hertfordshire.

‘When asked to estimate how much they could physically lift, those in a Superman T-shirt thought they were stronger than students in a plain T-shirt, or in their own clothing.’

It wasn’t just superhero clothing that affected a person’s state of mind, though.

In another test, women were ask to do a maths test in a swimsuit or wearing a sweater, with the latter group performing better.

Wearing a white coat, meanwhile, was found to improve a person’s mental agility.

And in the book she claims when women are stressed, they neglect 90 per cent of their wardrobe, choosing to dress up only to feel confident.

In addition to scientific research, Professor Pine said she also has ‘tips on how to feel happier and more confident with the right clothes, explaining not only that we are what we wear, but that we become what we wear.’