Hi Anya, how’s your day been?

Pretty chilled. Doing press for this movie has actually been pretty wonderful because people are receiving it so well.

How do you think you’d manage doing a whole load of press for a movie people didn’t like or one that you didn’t like?

I’ve often thought about it actually, because at the beginning, when I first started doing press, there’s no way of preparing for it, so I used to give myself a really hard time and I would think ‘thank God I love the film’ – because otherwise it would be stressful. It’s fun to talk about a movie like this where it is quite dark and funny.

It’s interesting that you’re at an early stage in your career and you’ve stayed within such dark territory from The Witch to Split to The Miniaturist and now Thoroughbreds. Have you always been more attracted to fiction that focuses on darker issues?

Movies-wise, I’d love to be able to say that I’ve thought about it and I had a whole trajectory planned, but I didn’t. I was just connected to my characters and they happened to inhabit very dark worlds. Fiction-wise, though, and in my own self, I love fairytales, the Hans Christian Andersen ones. I think there’s such a humanity in darkness and pain. In terms of working in movies, it’s really fun to play out dark stuff because you get to feel out the extent of your emotions and your brackets of what’s acceptable are so much wider in those types of films so it’s fun to play.

The film features one of Anton Yelchin’s final performances. What are your memories of working with him?

Anton and I are great friends. We’re all people at the end of the day, so it’s always difficult to lose someone who means so much to you, but what’s really wonderful about being able to talk about him in the film is that from one point of view, while it’s hard to talk about him as a person, as an artist he’s so unique and so incredible. He was fascinating to watch and to work with and there’s this unanimous love for him, every single screening we go to, he has touched and affected so many different people.

In the film we have two young female characters who don’t really have much use for the men around them and they remain firmly in control of their lives. As a 21-year-old female actor in Hollywood, I imagine you’ve been offered a lot of thankless daughter and girlfriend roles with far less agency …

I’ve been very lucky, actually, in terms of the team that I have around me, who have filtered out most of those roles. Most of the women not only that I’ve been lucky enough to play but that I’ve read are quite complex, messy, interesting human beings – but then again I shouldn’t be the anomaly here, I should be the norm. Definitely, whenever I’ve got a girlfriend role, I’ve sent it back being like ‘Eh? Why?’ I’m excited for this era of women that we are stepping into right now where people understand that everyone’s a person and they’ve all got a lot more going on underneath the surface than you might originally think.

You mentioned this new era that we’re now in and even within the four years that you’ve been working, what have been your experiences of discrimination?

I’ve seen very casual sexism that’s interesting because the men that I’ve been lucky enough to work with and adore as friends, they’ve never treated me as anything different, they’ve always treated me as a co-collaborator. But randomly certain comments will come in and I’ll think, ‘You don’t know any better, you don’t understand what you’re putting on me.’ It’s the way that society has taught you about how it’s acceptable to talk to your opposite gender. So it’s been interesting watching people become aware of how casual sexism really does affect somebody. It’s not just men: it’s also women understanding that they don’t have to put up with it and instead saying, ‘That’s not cool, that’s not an acceptable way to talk and this is how it’s made me feel.’ If you’re being honest about it then I’ve been lucky and the men I have come into contact with have been instantly apologetic and will say ‘I’ve never even thought about it in that way.’

You’ve said before that fame isn’t really of interest to you, but as someone who’s about to star in the X-Men spin-off The New Mutants, doesn’t the thought of the inevitable rise in status intimidate you?

Despite the fact that I’m a horrific overthinker, when I’m working I’m so focused on the character and the job at hand that the only time that I’ve ever really thought about it is when I get asked. I’ve always felt that I’ve been very lucky that I’ve been acting for four years and I haven’t really had any time off. I’ve just gone from film to film to film. I’m really glad that things have worked out that way for me because I don’t have time to think about it. I’ve only got time to focus on what I’m supposed to be doing at that current moment in time and hopefully if it’s going to happen it’s going to sneak up on me and before I know it, my life’s changed and I have to adapt rather than having the horrible fear of becoming less anonymous. There’s a beauty in being anonymous, there’s a reason why we’re actors, we’re playing other people so I think the idea of someone being interested in me, I’m quite a private person, is a bit daunting but I try not to think about it.

Do you think this is why you work so much, to avoid having all that excess time to think about it all?

Ah, you’ve hit very close to home. When X-Men got pushed [the release was recently delayed by almost a year], there was definitely a moment of fear just when I thought, ‘Oh my goodness, I now have all this time to think about it,’ when it felt like it was a running train and I was just going to jump on it and it was gonna be whatever it was going to be. I’ve hopefully matured and just thought, you know what: life is going to throw at me whatever it’s going to throw at me, and so I’d have to just enjoy. It sounds so trite and over-Instagrammed but be in the present, be in the moment and really relish it – because if you live too much in the future you’re just going to drive yourself mad.

You’ve also just wrapped Glass, the film that will act as a Split and Unbreakable sequel. I imagine you’re sworn to secrecy given that it’s an M Night Shyamalan film but what can you tell us without getting into trouble?

I can’t tell you very much plot-wise, but I can tell you what the ambience on set was which, by the way, what an incredible set to be a part of. I sort of woke up, because I’ve been working so hardcore, I just suddenly woke up from a dream and I was at a table with Bruce Willis, Sarah Paulson, James McAvoy and Samuel L Jackson, and I was like, ‘Oh my God, what am I doing at this table?’ Everybody is so aware of how special and unique this project us. I mean, the man’s been working on it for 17 years.

And can we expect more within this newly crafted universe?

There is no point trying to guess what M Night Shyamalan is going to do. He will outsmart you, he will do something completely unexpected and that’s exactly how I like it. So actually, with Night, it’s one of the few situations where I don’t overthink because I just let him go for it.

• Thoroughbreds is now out in the US and will be released in the UK on 6 April