If you’ve got a sibling, there’s a good chance you’ll have experienced that relationship as a rivalry. You might even have your own tales from childhood, later evolving into urban legends that still have conflicting testimonies all these years later. We know, they started it.

Polish photographer and Lodź Film School graduate Karolina Wojtas is gaining a reputation for her bright and busy images imbued with an experimental, childlike energy. After an initial delay caused by Dutch lockdown restrictions, she is bringing her relationship with her younger brother to life in a riotous solo exhibition in Amsterdam called We Can’t Live – Without Each Other.

The idea evolved from an amusingly dramatic recollection: that when Wojtas was around four or five years old, she was asked if she wanted a brother or sister, to which she responded that she would chop up said sibling with an axe and eat them up.

Thankfully she had a few more years to think on it. Her brother arrived when she was 12 years old, an age gap that she says doesn’t fit the bill of what people expect of a typical brother-sister relationship. As she recalls, “I took care of him, but always I was scared that someone could think that he could be [my] son”, although she suspects this has something to do with watching too many TV shows on teen mums at the time.

In need of new work to enter the ING Unseen Talent Award a few years ago (which she went on to win), Wojtas thought her brother would make an ideal candidate to appear in a project, and so began a series about their relationship. She appears in the series too, though less often – something she hopes to balance in the future. Although they sometimes tried to plan the images, the outcome was usually more unpredictable. The result is a clash of colours and fake injuries, from blood and bite marks to one especially startling photograph of plastic smothering her brother’s face.

“I didn’t even think about it, we just cleaned our room,” Wojtas says of how that photograph came to be. “My brother got bored and he didn’t want to collect trash, he just put bags on his face. So I took my camera and just took a photo. So it was an ordinary daily situation. Mostly we were just playing and having fun with ketchup and toilet paper at our home.”

Like many sibling relationships, the body of work is full of contradictions: it’s at once twisted and joyous, unnerving and endearing. Wojtas is keen to point out that it is all a fabrication: “Our relationship is great, we love each other, the whole project is fake, so don’t be scared. He is okay.”

At the Foam exhibition, the photographs have been divided (Wojtas on one side, her brother on the other), blown up to huge proportions and stacked as floor-to-ceiling installations almost five metres tall.

“I wanted to play with a scale that when you were a child, everything seemed to be enormous,” she says. It’s an installation that, even by her standards, is a “little ridiculous”. The hope is that it will inspire some playfulness in visitors. “People need to touch it, pull up images, to see what is hidden inside layers,” she explains, “but I would like to encourage you to do it in groups and help each other to handle this huge piece.”

For Wojtas, the relationship between siblings is a vital one in families. “Sibling relations should be the most important,” she says. “Often you share the same memories, problems, which helps to deal with [them].” Even though in this series Wojtas and her brother are recreating the image of a “real brother-sister relationship” that’s closer in age, the dynamics were clearly already there. “In reality, I am more childish than my brother,” she admits. “I always have stupid ideas to play, and he always asks why I am so dumb.”

We Can’t Live – Without Each Other runs at Foam, Amsterdam until April 10; foam.org; karolinawojtas.com