Once at the Academy, Nog sets his sights on Red Squad, an elite cadet group that only the best get to join. He ends up among their ranks when he and Jake are rescued in a battle zone, and he’s thrilled to receive a field promotion and the position of Chief Engineer. Unfortunately, Nog is so eager to be part of this team of high-achievers that he ignores the warning signs of their dysfunction.

Nog takes naturally to the disciplined life of a Starfleet officer. He even intimidates his dad when he returns from the Academy, and he bosses Jake around when they room together. He takes responsibility for training a rambunctious group of Ferengi to be a fighting force capable of rescuing his grandmother, a task that does not come without great frustration. Even when he’s hiding out in a holosuite world, he helps the lounge singer Vic turn his establishment into a bigger and better business.

When Klingon forces begin posting to DS9, Nog makes it his personal mission to gain their respect by confronting them on their unruly behavior, despite being literally half their size.

Thanks to his hard work and the attrition from the war, Nog goes from cadet to Lieutenant (j.g.) in just three years.

Auxiliary Function: (Si) Introverted Sensing, “The Study”

Even though Nog breaks from his people’s tradition by joining Starfleet, he’s still a Ferengi at heart. He recognizes the positive traits he’s inherited from his culture, his father, and his uncle that will help him succeed in Starfleet. He does take a long time to overcome some of his ideas about how to treat women, and he brings a bribe to Captain Sisko when asking for his recommendation—the requisite Ferengi gesture when choosing a mentor. He still holds on to his money, too, even when Jake tries to persuade him to use it to buy the Captain a baseball card (when Jake explains that he doesn’t need money as a Federation citizen, Nog replies, “Then you certainly don’t need mine.”).

Nog also retains his spiritual roots. The Ferengi believe in something called The Great Material Continuum—like the Force, but for money and material goods. It’s this belief that sustains him when he borrows and trades for the spare parts Chief O’Brien needs, always trusting that the Great River will provide. And of course, he never forgets the Rules of Acquisition.

Nog values healthy routine, and tries to encourage Jake to join him in an exercise regimen when they move in together. His appreciation for the establishments of Ferengi culture gives way over time to his respect for the institution of Starfleet. His head for thoroughness and details gets him the recommendation from Sisko after he turns in an inventory with items even the station crew missed. His good ears help Kira solve a series of murders.

Nog’s development as an officer stumbles a bit when he loses a leg in combat and can’t get over the trauma. He keeps reliving the moment, and claims he feels pain in the leg that isn’t there anymore. He retreats into a comforting holosuite world for a while, only coming back to reality in careful steps, supported by his family.

Tertiary Function: (Ne) Extraverted Intuition, “The Hiking Trails”

Nog wants something better for his life than spending his years working for his uncle in a bar. He recognizes his father’s untapped potential and is terrified of going the same direction. Sensing greater opportunity in Starfleet than Ferenginar, he becomes the first Ferengi to join the Academy.

Nog has to learn a whole new way of life once he’s part of Starfleet, but he has a head start thanks to his boyhood friendship with Jake Sisko. They both challenge each other over the years with new ideas and new perceptions of the world. With that and his father’s gift for creative problem-solving, Nog excels quickly on his new career path.

Inferior Function: (Fi) Introverted Feeling, “The Deep Well”

When a Bajoran coup forces everyone to evacuate the station, Jake and Nog are separated only a year into their friendship. Jake’s anxious, but Nog believes in their bond. No Human and Ferengi has ever been better friends than they are, he says, so they won’t be kept apart for long.

Winn does try to do some good. As a young ranjen, she convinced her superior to take a more active role in fighting the Cardassians, and was able to use gemstones from the tabernacle to bribe Cardassians for small acts of kindness. This saved a precious handful of lives. She confronts Kira for acting like only the members of the Resistance put up any kind of fight during the Occupation.

Winn is outspoken as head of her order, though she’s disappointed that they don’t have as influential a voice as she thinks they should. She sees the Federation and its allies as intruders who will negatively influence Bajoran culture, and leads a boycott against Keiko’s school on charges of blasphemy. The whole show is secretly an assassination plot against Vedek Bareil, her chief rival for the position of Kai, and a more progressive and popular leader than she is.

Whenever someone else threatens to steal her spotlight, Winn’s conspiratorial wheels start churning. She supports the return of the long-lost Akorem Laan as the new Emissary rather than Sisko—that he brings back the traditional caste system doesn’t hurt either. She digs up dirt on Bareil during the election for Kai, which wins her the position, and then makes friends with him when she needs his assistance to negotiate a peace treaty with Cardassia. He’s mortally wounded during the process, and Winn pretends to care about his physical well-being just long enough to complete the talks.

Then she decides he should die with dignity.

Shortly thereafter, Winn wiggles her way into the temporary position of First Minister, a blatant and dangerous combo of church and state. When Kira and former resistance leader Shakaar stand up to her, Winn acts deeply offended. But she quickly offers a statement of support for Shakaar once he’s elected the new First Minister.

Winn briefly begins to come around to Sisko when he discovers the lost Bajoran city of B’Hala. She helps him through his troubling visions, showing true concern and care, and really seems to speak from the heart when confronting Kira about her distrust of her motives and courage. Her diplomatic skills even shine when she negotiates a non-aggression pact between Bajor and the Dominion, assuring the obsequious Weyoun that they are nothing alike, “Nothing at all.”

But Winn’s insecurity gets the best of her, and she returns to her old ways when Sisko tries to unleash the Reckoning. She just can’t live with the idea that Bajor’s fate would be decided by a foreigner, and so she interrupts the process, claiming she did it to save Sisko’s son. Once she starts receiving visions from the Pah-wraiths, Winn tries one more time to redeem herself by confessing her problem—and her pride—to Kira.

Kira recommends that Winn step down, and the Kai feels immediately insulted that she should give up her position after years of faithful service. She resents that the Prophets have never personally spoken to her, and refuses to humble herself to them. Eventually, she gives herself over to the Pah-wraiths, and to a relationship with Dukat, and together they plot the destruction of Bajor.

Traditionally, XNTJs are the ones typed as the villains who want to destroy everything, but when an Fe-dom villain decides that everyone must pay, everyone better watch out.

Auxiliary Function: (Si) Introverted Sensing, “The Study”

It’s easy to forget that every Bajoran we meet on DS9 only recently came out of a period of great suffering. Winn keeps her condescending composure quite well, but she tells Kira that she remembers “each and every beating” the Cardassians gave her during the Occupation. Though she’s never known the touch of the Prophets, Winn’s resilience in these times seems to serve as the one true touchstone of her faith.

That her endurance is never rewarded by the Prophets angers her deeply. Perhaps she’s looping too hard to appreciate her own personal experiences, reaching for an idealized religious experience that she imagines everyone else has had. When she finally turns on the Prophets, it’s after years of feeling neglected by them.

Till then, Winn holds to the orthodox practices of the Bajoran faith. She doesn’t want non-Bajoran scientific principles taught in the school, and she supports the old caste system during its brief return. She’s distrustful of outsiders and wishes the Prophets had chosen a Bajoran (maybe her?) as their Emissary.

Tertiary Function: (Ne) Extraverted Intuition, “The Hiking Trails”

Winn’s a master of pretense, quickly changing allies and stories to go with the flow of public opinion. Her ambition pushes her into greater positions of power, often before she’s had the experience to know what to do once she gets there. Though she’s initially frightened at the thought of leaving the religious establishment she spent her life in—and allying herself with Bajor’s greatest enemy—once she gives up the Prophets for the Pah-wraiths, she feels a delicious freedom she’s never known before.

Inferior Function: (Ti) Introverted Thinking, “The Laboratory”

In private moments, Winn will sometimes let down her smiling façade and bite back at those who dare criticize her. She’s anxious and panicky in moments when she realizes her ambition has bitten off more than she can chew, and can't discern her options. She’s cold and calculating in her grabs for power, and can dismiss the lives she must step on in order to get where she believes she deserves to be. Once her faith fails her, she sees the hard truth of her own hypocrisy, and then blames all her problems on the Prophets and the Bajoran people themselves.

Quark endures a moral dilemma when he’s forced to break a contract with another Ferengi—something the Rules of Acquisition expressly forbids. He’s willing to kill himself to fulfill the deal and avoid violating his society’s customs. After a vision from the Nagus who wrote the Rules (an Ne-experience that encourages him to see the Rules in a new light), he stands his ground and saves his own life. He pays the price by getting cut off from doing business with all other law-abiding Ferengi—basically exile.

Quark’s horrified to find himself acclimating over time to Federation culture, picking up on their equality, generosity, and taste for root beer. But as an Fe-dom, Quark can’t help this process. It’s the reason he’s a bartender in the first place. He complains to Garak that he could have gone into any line of more lucrative business—like weapons sales, for instance, which earned his cousin Gaila his own moon.

The reason he didn’t? “I’m a people-person.”

Weapons sales are too cold and technical, and Quark likes showing people a good time. He likes talking to them, entertaining them, tending to their needs and desires with food, drinks, games, and holosuite programs. He often feels used and underappreciated when the Starfleet officers he serves faithfully insult him, when his brother leaves the bar for a new job, or when his customers get distracted by another establishment. He’d be bored anywhere else but at his bar, the center of attention, telling stories of his financial exploits—or exaggerating his fight with a Klingon to pull in more eager customers.

Of course, Quark’s happy to exploit and manipulate said customers. That’s Quark’s genius. He always wants something from you, but he knows how to get you what you want in return. His strategy when facing any antagonist, whether a grumpy security officer or a stubborn business partner, is appeasement, mutual compromise, and negotiation. He always searches for a solution that will be profitable for both parties—because that’s good business.

He persuades a cold-blooded Vulcan terrorist that making peace is the most logical—and cost-effective—thing to do. He convinces the Prophets to restore Grand Nagus Zek’s personality by preaching the positives of greed and ambition. He takes charge of a motley band of Ferengi and leads them in the rescue of his mother from the Dominion, which he negotiates with one of the notoriously slippery Vorta. There is virtually no situation Quark can’t work to his advantage with some smooth talking.

It’s this gift that his cousin Gaila makes use of when he needs someone to host his clients for weapons sales. And Quark’s great at it. The cousins make money hand-over-fist, with Gaila and his boss handling the goods, and Quark handling the hospitality. Unfortunately, Quark’s conscience gets the better of him, and he ends his weapons career by skillfully manipulating deadly enemies against each other rather than helping them to kill millions.

For all his greed, deceit, pettiness, and misogyny, Quark holds a high moral opinion of himself and his people. He gives almost as many righteous speeches throughout the course of the series as Sisko does, defending Ferengi ways against the patronizing humans who look down on him. In one of his best, he points out that as distrusted as the Ferengi are, they have nothing like the wars, genocide, and other barbarity found in human history.

“We’re nothing like hew-mons,” he concludes. “We’re better.”

Auxiliary Function: (Si) Introverted Sensing, “The Study”

Quark has memorized his people’s guiding principles, all 285 Rules of Acquisition, and can recite them at will for guidance in virtually any situation he encounters. Quark cherishes Ferengi tradition and culture, and wants to hold on to the form of it he remembers. When his family, and eventually his Nagus, start upending the old customs, Quark resists. His last big scene in the show is a fiery speech in which he declares Quark’s Bar to be the last stronghold of true Ferengi culture.

Quark’s fashion sense looks garish to the non-Ferengi eye, but it’s perfectly in keeping with expected Ferengi standards for a man of his status. He’s detail-oriented about his bar—there’s always a chore to give his workers to keep the place spotless. He has a good memory for his customers—he knows their likes, dislikes, and vices.

Of course, his hearing is ultra-sensitive, and he can determine the exact decibel level needed in the bar to make sure it’s a lively, profit-producing place. At the end of the night, he enjoys the routine of counting out the profits, and has a fond appreciation for the feel and weight of latinum. He’s run his bar for years before the show even begins, and though he has to be blackmailed into staying on, he’s largely happy to keep working there despite his protestations of greater ambition.

He also has the last line in the show: “The more things change, the more they stay the same.”

Tertiary Function: (Ne) Extraverted Intuition, “The Hiking Trails”

Quark’s willing to try anything to make a profit, and his creativity knows no bounds. He has to move quickly to stay ahead of a certain stubborn constable, and tries many an idea to beat his adversary. Though frequently frustrated, he’s always able to put aside a failure and move on to the next scheme.

When he’s trapped on the Defiant with an undetonated torpedo and an uncooperative business client, Quark demonstrates that taking a risk on life’s possibilities is often the best way to live. In any given negotiation, Quark can turn on a dime and adjust his strategy to meet the changing situation. While other Ferengi like his mother and the Nagus are more long-term strategists (Ni-users, both of them), Quark tends to play it by ear, if you will.

On the other hand, Quark refuses to consider changes to Ferengi culture. Though his brother Rom explains the benefits of the many reforms begun by their mother and the Nagus, Quark can only see what they’re losing. He grows more cynical and suspicious the further they depart from tradition.

Inferior Function: (Ti) Introverted Thinking, “The Laboratory”

Quark’s cloying, Feeler approach doesn’t tend to fly with Odo, so he has to get wily. His infamous Ferengi deviousness gets to work to save his hide from many a predicament. He dazzles the Klingons with numbers and financial analytics in order to save the house of his temporary bride Grilka. He watches his profits on an hourly basis to determine the success of his business. Rom complains that when Quark has a problem to solve, he stays up all night noisily grinding his teeth.

Quark grows pessimistic and critical in dark times when his profits and opportunities are threatened. He’s ready to give up and get out after the Occupation, and years later, he doubts the Federation’s ability to save them all from the Dominion. When his brother, family, or employees disappoint him, he insults and criticizes them, finding fault with everything they do.

After being cut off from his Ferengi business connections, Quark sees his profits disappear and can’t determine a way to fix his situation. He falls into a deep depression and must return home to his Moogie to figure out what to do. Once there, he’s offered a chance at Ferengi redemption by plotting the breakup of Ishka’s secret relationship with Grand Nagus Zek.

Leeta’s a good judge of character, and sees potential and lovability in Rom long before he does. When he starts a labor union, she helps get the bar employees on board, and encourages Rom in his cause. She waits for him to make the move when it comes to romance, which means she has to wait quite a while. When they have an argument that almost cancels their wedding, she has to vent to her friend Kira, an Fi-dom who patiently listens and then bluntly tells her she doesn’t really mean the angry things she’s saying.

Leeta leaves the station just before the Dominion invasion, accepting Rom’s wishes to keep her out of harm’s way. Before long she’s back, working the Dabo table while secretly joining Kira’s resistance. Now she’s the one fearing for Rom’s safety, as he’s been captured for his sabotage—but Rom doesn’t want to be rescued.

Leeta and Quark, anxious ESFJs that they are, can’t accept this, and they argue with Rom about how stupid he is for refusing their help. Leeta experiences a similar barrier when Nog returns from his surgery after losing his leg. Ezri has to hold back Leeta, now Nog’s step-mother, from comforting her traumatized step-son until he’s ready. When he is, Leeta joins in the family hug to welcome him back.

Auxiliary Function: (Si) Introverted Sensing, “The Study”

Leeta appreciates her Bajoran heritage, introducing Julian to the Rite of Separation when their relationship ends. She wants a traditional Bajoran wedding, and resists Rom’s efforts to get her into something more scanty for the ceremony. In her day job, though, she’s very comfortable in her own skin, and always looks great. She’s so comfortable, in fact, that she answers the door of her quarters without realizing she’s lost her towel.

(And a bit of non-canon info from the post-TV novels, because I think it’s cool: Leeta’s full name was never given because she was orphaned during the Occupation and never knew her family. Once she married a Ferengi, whose people have no family names, it didn’t matter anymore. She stuck quite happily with her single, unique name.)

Tertiary Function: (Ne) Extraverted Intuition, “The Hiking Trails”

Like any Bajoran who had to survive the Occupation, Leeta can be flexible and adaptable. After a few years of working at Quark’s Bar, she experiences anxiety over the lack of direction in her life, feeling like she should do more, and accepts a position at a distant starbase running their café. When Rom confesses his love to her, she changes course again, starting a new life as part of a Ferengi family. She sees the potential of Rom’s labor union, and demands more and better pay from Quark.

Inferior Function: (Ti) Introverted Thinking, “The Laboratory”

When she puts her mind to it, Leeta can be quite formidable. She studies up on the Trill zhian’tara ritual, and helps Jadzia explain it to the group. She’s insulted that Quark thinks she has no brains, appreciating her only for her physical assets, but she puts up a fight more than once when she figures out she can argue for better working conditions.

When she and Rom reach an impasse about signing a pre-nuptial agreement, she breaks off the engagement and complains to Kira about him. She’s trying very hard to convince herself she doesn’t like him, picking at any fault she can think of. But Kira knows she doesn’t mean it, and they eventually work out the problem.

The Founder is supremely confident and implacable even in the face of setbacks. She always believes the Dominion will succeed, and repeatedly tells her enemies how doomed to failure their efforts are. She’s completely intolerant of failure and incompetence, and grows more demanding with her subordinates as the war drags on.

Auxiliary Function: (Si) Introverted Sensing, “The Study”

Millennia ago, Changelings were hunted down by solids who feared and distrusted them. The survivors formed the Dominion, and began conquering the solids in an effort to ensure that they were never persecuted again. The Founder sees all non-shapeshifters through the lens of this story, and won’t accept them as anything other than dangerous, small-minded brutes.

She finds existence as a humanoid limiting compared to the way she lives when she’s at home in the Great Link. Though she describes the Link to Odo in abstract terms, I don’t think this puts it outside the realm of sensory experience. Si, because it’s personal to the user, can feel abstract and hard to describe, like any other Introverted function.

Odo’s Si-experience is usually of being in one form, while The Founder has been many different shapes and beings over the centuries. She can replicate anything or anyone down to the last tactile detail, and shares the experience of all the other Changelings she’s with in the Link, who have also taken many forms. Thus her life experience is multi-faceted and expansive, and she very naturally feels that she is wiser and has more understanding of the universe than solids trapped in one form. That she refuses to consider their perspective until Odo links with her betrays the hidden rigidity of her thinking.

Tertiary Function: (Ne) Extraverted Intuition, “The Hiking Trails”

The Founder takes pride in being a shapeshifter, and gets bored and frustrated having to stay in the shape of a humanoid for too long. She pushes Odo to think outside the box (or bucket) of his bipedal existence, to experience the essence of different objects and lifeforms. She uses language that sounds mysterious and abstract to him as she describes life in the Great Link, hinting that she may be not so much an individual, but a “drop” of the Great Link that “becomes the ocean” when she returns.

On the other hand, the Founder’s ideas of humanoids have solidified, if you will, and she will not be moved in her perception. She tries love-making in the humanoid style, and is not impressed. When she’s infected with a wasting disease by Starfleet’s secretive Section 31, this only confirms her cynical view of humans. As her war efforts begin to fail, she begins to loop, ordering the swift execution and re-cloning of her Vorta scientists to provide a fresh perspective on their work to cure her.

Inferior Function: (Fi) Introverted Function, “The Deep Well”

The Founder pursues her mission to dominate the galaxy with an air of moral superiority. She believes that Changelings are a higher life-form than all non-changelings, giving the Founders the right and duty to conquer. She needs allies like the Breen and the Cardassians to build her forces, but she still views them with disdain, and will manipulate them to serve her purposes.

Her greater mission, beyond conquering the Alpha Quadrant, is to bring Odo home. She’s tender and patient with him, repeatedly inviting him to return to the Link. She and the other Founders feel forced to punish Odo for breaking their one rule—that no Changeling ever harms another Changeling—but once his time is served, she once again entreats him to join their ranks. Though he has chosen life with the solids, she assures him that he will always be a Changeling in the eyes of his people.

The Founder grows testy as the infection breaks her down, and the Alpha Quadrant refuses to surrender to her will. She denies her condition at first, not wishing to show weakness, but then she stops caring how anyone sees her. She bullies, criticizes, threatens, and abuses her subordinates. She orders mass executions of Cardassians to punish the insurgent movement, and then orders the whole planet wiped out when it looks like the Dominion has lost.

Joseph speaks up loud and vocally when forced to take a blood test thanks to Ben’s new planet-wide security measures, making such a fuss that he gets arrested. He’s hurt that Ben won’t simply trust him. Nevertheless, Joseph is always supportive of whatever Ben needs to do, especially if it’s a tough decision. He has a history of letting Ben brood for a while before gently pushing him into action—first in asking out his boyhood crush, and later in making a move to stop Admiral Leyton.

It’s a very healthy example of an Extraverted-Judging-dominant parent counseling their Extraverted-Judging-inferior child to use their lower function more effectively, and I think it accounts for the relative health of Sisko’s Te compared to other INFPs.

When Joseph finally makes the trip out to DS9, he shows up just when Ben has learned of the death of a friend in combat, and he helps his son talk out his grief.

Auxiliary Function: (Si) Introverted Sensing, “The Study”

Joseph possesses legendary cooking skills, honed over decades, passed down from generation to generation. He keeps secret recipes that he carefully teaches his son and grandson (and disapproves of his daughter’s careless use of cayenne pepper in the sauce), and suggests Jake open a Creole restaurant on the Promenade to keep the Sisko legacy alive. Goodness knows Joseph himself won’t open up shop on the space station. He loves his home, his restaurant, and his planet too much to leave. He’s never left Earth until his visit to DS9.

That’s a long time to live in one place, and despite his health concerns, Joseph intends on living at least another 50 years (hinting that the human life span in the Star Trek future has reached about 130).

Joseph seems resistant to the idea that his body is getting older. He thinks his doctor is an idiot for not knowing the difference between Cajun and Creole, so why should he follow his instructions about anything else? Besides, Joseph worries about what will happen to the restaurant in his absence.

Joseph finally does make out to DS9, and seems overwhelmed. All he can say to Kira is that, “It sure is big.”

Tertiary Function: (Ne) Extraverted Intuition, “The Hiking Trails”

Joseph gets a kick out of making up stories to entertain and frighten his grandson as a boy, getting him to believe that the stuffed gator hanging from the restaurant rafters comes to life every night. When Ben journeys to Earth to meet with Starfleet HQ, Joseph discerns that the situation must be serious for them to send for Ben from so far away. He grows more worried and suspicious of all the restrictive changes being made by Starfleet security in the wake of the Changeling scare.

As rooted to his home as Joseph is, he can change his ways when needed. Thanks to Nog’s influence, he considers adding tube grubs to his menu (though he’ll have to cook them to satisfy his human customers). He eventually journeys to DS9 for a once-in-a-lifetime visit, though once he’s there, he’s mildly upset to learn that his son thinks their whole life might be the dream of some writer.

Inferior Function: (Ti) Introverted Thinking, “The Laboratory”

Joseph is stubborn and critical of Ben’s declaration of martial law. He resists taking a blood test and gets arrested for it. He points out the flaws in the blood test method, suggesting different ways a Changeling could fool the test by soaking up blood from a human victim.

Ben’s inferior Te shouts at his father, “Why can’t you just do as you’re told?” while Joseph’s inferior Ti tears apart his son’s methodology. He argues enough that Ben eventually breaks down and tries to find a new solution to the security problem. It’s a great clash of types and functions, and fortunately, father and son care enough about each other to learn from the fight and repair their relationship.