Functional Order: Fi/Ne/Si/Te
Dominant Function: Fi
She approaches science and greater understanding from a place of warm human conviction and focus, and finds it abhorrent that Brand would mislead people with “hope” rather than find a way around a problem he sees as insurmountable. From the start, she personalizes her experiences, leading her to form conclusions about her “Ghost” – she recognizes it was her father not through analytical thinking, but a deeper emotional understanding and comprehension, just as she fully trusted her own instincts and the message that told him to STAY with her. She considers his departure a deep betrayal and refuses to speak to him for decades, furious at his absence and unwilling to forgive him for leaving her behind. It’s only when she finds him again, through the dust, that she can forgive him and move forward.
Auxilliary Function: Ne
Murph has an instinctual ability to sense there is “more” beyond than what is apparent – which starts out in childhood, with the mysterious things happening in her room. Rather than simply discount it, or write it off as an anomaly, Murph tries to figure out ways to communicate with her Ghost – and realizes it’s using Morse Code. She also personalizes the Ghost, and years later, returning to the evidence with her newfound understanding of her father’s space mission, recognizes that time bends on itself and her father is / was her ghost. His future, her past. She also, after working for a time with Professor Brand, realizes that he has lied to them this entire time – he has been deliberately leaving out a piece of the equation, which would show humanity it’s hopeless. Murph then goes on to factor in her father’s information, complete the equation, and save the human race. And she does it all in “real time” as things are happening around her (Ne).
Tertiary Function: Si
She has far less sentiment than her brother (an ISTJ) about the place where they grew up, but needs to relive moments of her childhood to piece together the connections required to solve the puzzle of her past, present, and future.
Inferior Function: Te
She also falls into aggressive low Te behaviors, such as burning down her brother’s corn field when she knows it’s not safe for him to stay there anymore and he will not listen to reason.
Note: This argument has been taken from Funky Mbti in Fiction, where she is typed as ENFP.