In contrast to her delicate physique - rail-thin and only 1.57 metres (5ft 2) tall - Mara is regularly cast as a take-no-prisoners archetype, as evidenced by her two current roles. She exudes a gritty quality on screen, not dissimilar to that of her similarly diminutive younger sister, Rooney Mara, 29, who earned an Oscar nomination for The Girl with the Dragon Tattoo, in 2011.
"I'm not afraid of playing characters that aren't likeable. I gravitate towards darker roles and in both Transcendence and House of Cards, I'm playing these very strong, ballsy women but that's just a coincidence."
The successful siblings hail from one of America's most prominent football dynasty - they are the great-granddaughters of the founder of both the New York Giants and the Pittsburgh Steelers.
"Acting was very, very foreign to me when I first started, especially coming from the football world. Football is a passion of mine; it's in my blood, literally, and I grew up on it. The first Superbowl I went to was in utero."
Interestingly, Mara insists that there is no rivalry between her and Rooney, though they are of similar age and physical type. "I come from a huge close-knit family and my sister and I are very close in age. Until Rooney began acting I didn't have anyone to talk to about the disappointments and joys of the job, so I feel really lucky that we share the same passion," she says. "We'd really like to work together one day, though we have nothing lined up as of yet."
Born and raised in the New York state suburb of Westchester County, the elder Mara's interest in acting began at the age of 9 in school productions and community theatre. She landed her first TV role in Law & Order in 1997 when she was 14, and made her film debut in Random Hearts, in 1999. She also starred in Brokeback Mountain (2005), Shooter (2007), and 127 Hours (2010), looking quite different in each role, and has appeared on TV in Nip/Tuck, Entourage, and American Horror Story. Her red carpet appearances are always original and she is earning herself a reputation as a fashion icon.
This quietly-spoken, intense young woman seems rather bemused by this particular form of attention. "Being an 'It Girl' is not a reality to me, though it's flattering to hear it. The red carpet used to be absolutely terrifying to me but now I understand that it's part of the work. And fashion seems to have seeped into my life. When I'm playing a character it always ends up affecting my wardrobe choices as a person.
"When I was shooting Transcendence, I was definitely wearing darker colours, and when I was shooting House of Cards, I would end up wearing lots of things that Zoe Barnes would wear, like hoodies. Actually, both Rooney and I love fashion and we totally talk about that stuff a lot."
Mara will next play Sue Storm/The Invisible Woman in a reboot of The Fantastic Four due for release next year.
"I'm really not a comic book girl and I haven't seen the other films in the franchise so this world is very unfamiliar to me. I haven't tried on any spandex yet, but it's all good," she laughs.
"I want to do all kinds of roles. Playing a superhero is not the worst thing that can happen."
Who: Kate Mara
What: Transcendence, opens at cinemas Thursday.
Also: House of Cards, TV3 Sundays 10.30pm
- TimeOut