Functional Order: Fe/Si/Ne/Ti
Dominant Function: Fe
Katara judges and makes decisions based on her feelings, which usually circle around other people. She is very outgoing and friendly, having no trouble to start a conversation with strangers (for example Haru in “Imprisoned”). Because she feels so strongly for others, she can’t just turn her back on people in need (starting the revolution in the Earth Kingdom, helping the lake village in the Fire Nation in “The Painted Lady”) or take injustice (The Waterbending Master”). “I will never, ever turn my back on people who need me!” She holds the gaang together, taking charge and keeping her hopes up when everyone else has given up (“The Desert“). She’s very protective, even wanting to shield people from an ugly truth (“The Southern Air Temple“). Since she cares so strongly for everyone, some characters feel that she is too motherly (“The Runaway“). (anonymous) She wears her heart on her sleeve, telling everyone how she feels at any given minute. She tends to interfere and mother others, even those who are not related to her.
Auxiliary Function: Si
Being both providing and practical, Katara makes sure that the gang has all they need on their trip around the world. She mends her brother’s pants, buys supplies, and knows how to help as a midwife. She is a hard worker and learns to be a Master Waterbender that way, in contrast with Aang’s natural talent (“The Siege of the North, Part 1). Being so emotional and having an excellent memory makes Katara prone to hold grudges and finding it hard to forgive deep wrongs (“The Awakening,” “The Western Air Temple,” “The Southern Raiders”). She prefers familiar ground and doesn’t take much joy from new, physical thrills (contrast penguin sledding with the mail system roller coaster in “The King of Omashu”) or breaking the rules for fun (“The Runaway”). (anonymous) She holds on to her powerful subjective memories of a variety of incidents for a very long time, and allows them to shape her future. She often compares things to how they were before, like what she says to Aang in The Day of Black Sun Part 1.
Extroverted Intuition (Ne):
Katara is much more open to new ideas than her brother, though not as susceptible to them as Aang. She immediately embraces the idea of Aang being the Avatar and becoming his new family, she enjoys visiting the fortune teller, and challenges old systems if they are unjust. She can be creative in her ways to help others, for example taking up the guise of the painted lady, and she is able to connect things quickly, for example getting the clues and solving the mystery of a crime quicker than Sokka (“Avatar Day”). (anonymous) She’s frequently creative and thinks up fun new potential concepts.
Introverted Thinking (Ti):
Logic and analytical thinking don’t play much of a role in Katara’s decision making and more often than not she’s offended at Sokka’s rational approach to a situation in which people are involved. She strives to understand people’s motivation though and struggles when she can’t make sense of it. (anonymous) She’s usually open to reinterpreting ideas and tries to figure out the pieces of the information she’s learned.
Note: This argument has been taken from Funky MBTI in Fiction.